DCS Simulator configure program and troubleshooting

this course is for DCS simulator

1. DCS simulator for process panel operation

2. Knowledge and Elements Illustrate DCS & PLC Benefits, Usage and History. Overview of control system history. Control system benefits and usage. Types of control Develop Knowledge of DCS Components (Hardware & Software). Infrastructure [Communication Bus, Interfaces, Controllers, Gateways, RTU, Others]. Hardware and technologies. Software [Configuration, Graphics, Alarming, Trending, System Management, Others]. Extend Knowledge of DCS installation and Maintenance. Site Installation, Commissioning and Startup. Diagnostics, Spares, Tools and Power Distribution. Maintenance [Backup, Replacements and System Installation]. Develop Knowledge of PLC Components. PLC fundamentals. PLC Logic.

3. Control Systems

4. 1. Automation System Structure Although applications differ widely, there is little difference in the overall architecture of their control systems. Why the control system of a power plant is not sold also for automating a brewery depends largely on small differences (e.g. explosion-proof), on regulations (e.g. Food and Drug Administration) and also tradition, customer relationship. The ANSI/ISA standard 95 defines terminology and good practices

5. 1.1 Large Control System Hierarchy Administration: Production goals, planning Enterprise: Manages resources, workflow, coordinates activities of different sites, quality supervision, maintenance, distribution and planning. Supervision: Supervision of the site, optimization, on-line operations. Control room, Process Data Base, logging (open loop) Group (Area): Control of a well-defined part of the plant. closed loop, except for intervention of an operator) Coordinates individual subgroups Adjusting set-points and parameters Commands several units as a whole Unit (Cell): Control (regulation, monitoring and protection) of a small part of a group (closed loop except for maintenance). Measure: Sampling, scaling, processing, calibration. Control: regulation, set-points and parameters Command: sequencing, protection and interlocking Field: Sensors & Actors, data acquisition, digitalization, data transmission, no processing except measurement correction and built-in protection.

6. 1.2 Response Time and Hierarchical Level

7. 2. What is DCS? A DCS is an integrated set of modules with distributed functions. Multi-loop controllers (10’s-100’s) that connect to field devices Supervisory coordinating controllers Multi-loop operator stations and engineering stations Servers for system data management Control network for intercommunication External connections A DCS, throughout the whole system, must provide: Performance: control must be faster than the process. Determinism: control must always take the same time. Fault tolerance: redundancy; must fail to a known state. Security: must have access restrictions/controls.

8. 2. What is DCS? Even though performance , ease of use , and interoperability are key evaluation criteria for any control system software package, the following is intended to provide the manufacturing engineer with a concise list of control system software evaluation criteria. INTEROPERABILITY. This refers to the interaction of all control system hardware and software components at all levels. INTERCONNECTIVITY. This criterion is concerned with the transmission medium, which is constrained by the network topology and how efficiently the system’s components communicate with each other. DISASTER PROCESSING. This component is defined by the efficiency with which the software provides the operator with system failure information and the ease at which the operator is permitted to bring the system back to maximum operation after system failure. DATABASE. This refers to the software’s ability to maintain the system’s database.

9. 2. What is DCS? PROCESSES/DATA. This criterion is concerned with the variety of processes and data that can be controlled by the SCADA package. DIAGNOSTICS. The SCADA package’s ability to assist in the resolution of system failures is evaluated by this diagnostic utility. SECURITY. This component is concerned with the levels of security provided by the software. MONITORING/CONTROL Monitoring of a given process in real-time and control of that process, within preset parameters, is evaluated by this criteria. ALARM MANAGEMENT/LOGGING. This is the category for detecting, annunciating, managing, and storing alarm conditions. STATISTICAL PROCESS CONTROL. This is the portion of the SCADA package that evaluates the process data. Production and quality is greatly effected by this data. OPERATOR INTERFACE. The graphical user interface (GUI) is evaluated using this criterion.

10. 2. What is DCS? TRENDING. The software’s ability to display trending plots using historical and current data is considered in this category. REPORT GENERATION. The production of logs and reports using current real-time data and data retrieved from historical files is evaluated under this category. Due to the advancements in computer technology and low cost, a personal computer-based distributed control system can be installed for a fraction of the cost required just a few years ago. However, prior to selecting any piece of DCS equipment, first examine the existing equipment, in particular the smart controllers, for network compatibility. Then, examine and select the software to be employed .

11. 3. What is PLC? A programmable logic controller , also called a PLC or programmable controller, is a computer-type device used to control equipment in an industrial facility. The kinds of equipment that PLCs can control are as varied as industrial facilities themselves. Conveyor systems, food processing machinery, auto assembly lines …you name it and there’s probably a PLC out there controlling it. In a traditional industrial control system , all control devices are wired directly to each other according to how the system is supposed to operate. In a PLC system , however, the PLC replaces the wiring between the devices. Thus, instead of being wired directly to each other, all equipment is wired to the PLC. Then, the control program inside the PLC provides the “wiring” connection between the devices. The control program is the computer program stored in the PLC’s memory that tells the PLC what’s supposed to be going on in the system. The use of a PLC to provide the wiring connections between system devices is called soft-wiring.

12. 3. What is PLC? Let's say that a push button is supposed to control the operation of a motor. In a traditional control system , the push button would be wired directly to the motor. In a PLC system , however, both the push button and the motor would be wired to the PLC instead. Then, the PLC's control program would complete the electrical circuit between the two, allowing the button to control the motor. A PLC basically consists of two elements: The central processing unit The input/output system

13. 3.1 The Central Processing Unit The central processing unit (CPU) is the part of a programmable controller that retrieves, decodes, stores, and processes information. It also executes the control program stored in the PLC’s memory . In essence, the CPU is the “brains” of a programmable controller. It functions much the same way the CPU of a regular computer does, except that it uses special instructions and coding to perform its functions. The CPU has three parts: The processor The memory system The power supply The processor is the section of the CPU that codes, decodes, and computes data. The memory system is the section of the CPU that stores both the control program and data from the equipment connected to the PLC. The power supply is the section that provides the PLC with the voltage and current it needs to operate.

14. 3.2 The input/output (I/O) system It is the section of a PLC to which all of the field devices are connected. If the CPU can be thought of as the brains of a PLC, then the I/O system can be thought of as the arms and legs. The I/O system is what actually physically carries out the control commands from the program stored in the PLC’s memory. The I/O system consists of two main parts: The rack The rack is an enclosure with slots in it that is connected to the CPU. I/O modules I/O modules are devices with connection terminals to which the field devices are wired.

15. 3.2 The input/output (I/O) system Together, the rack and the I/O modules form the interface between the field devices and the PLC. When set up properly, each I/O module is both securely wired to its corresponding field devices and securely installed in a slot in the rack. This creates the physical connection between the field equipment and the PLC. In some small PLCs, the rack and the I/O modules come prepackaged as one unit.

16. 4. How is a DCS different from a PLC system?

17. 5. Redundancy and Fault Tolerance 5.1 Redundancy Hardware redundancy add extra hardware for detection or tolerating faults Software redundancy add extra software for detection and possibly tolerating faults 5.2 Fault Tolerance Error Detection Ideal check Check should be independent from system Check fails if system crashes Acceptable check Cost Reasonable check, e.g. monitor rate of change diagnostics Performed “by system on system components” E.g. power-up diagnostics

18. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Damage Confinement Error might propagate and spread Identify boundaries to state beyond which no information exchange has occurred Error Recovery Backward recovery State is restored to an earlier state Requires checkpoints Most frequently used Recovery overhead Forward recovery Try to make state error-free Need accurate assessment of damage Highly application-dependent

19. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Fault Treatment If transient fault: restart system, go to error-free state System repair On-line, no manual intervention, (automatic) Dynamic system reconfiguration Spare (hot or cold) Fault Coverage Measure of system’s ability to perform: Fault detection Fault location Fault containment (and/or fault recovery) Note: – Recovery implies that the system as a whole is operational – This does not imply that a “repair” occurred – E.g. duplex system with benign fault can recover to continue operation on one non-faulty processor

20. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Hardware Redundancy Passive (static) Uses fault masking to hide occurrence of fault No action from the system is required E.g. voting Active (dynamic) Uses comparison for detection and/or diagnoses Remove faulty hardware from system => reconfiguration Hybrid Combine both approaches Masking until diagnostic complete Expensive, but better to achieve higher reliability

21. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Passive Hardware Redundancy N-Modular Redundancy (NMR) N independent modules replicate the same function Parallelism Results are voted on requirements: N >= 3 TMR (Triple Modular Redundancy) Fault tolerant structures Fault tolerance allows continuing operation in spite of a limited number of independent failures. Fault tolerance relies on work redundancy.

22. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Static redundancy: 2 out of 3 Work by of 3 synchronized and identical units. All 3 units OK: Correct output. 2 units OK: Majority output correct. 2 or 3 units failure: Incorrect output. Otherwise: Error detection output.

23. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Dynamic Redundancy Redundancy only activated after an error is detected. Primary components (non-redundant) Reserve components (redundancy), standby (cold/hot standby)

24. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Work by and Standby

25. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Workby Fault-Tolerance for Integrity and Persistency

26. 5. Redundancy and Fault Tolerance 5.2 Fault Tolerance Hybrid Redundancy Mixture of workby (static redundancy) and standby (dynamic redundancy).

27. 6. Microprocessor Control For simple programming the relay model of the PLC is sufficient. As more complex functions are used the more complex VonNeuman model of the PLC must be used. A computer processes one instruction at a time. Most computers operate this way, although they appear to be doing many things at once. Input is obtained from the keyboard and mouse, output is sent to the screen, and the disk and memory are used for both input and output for storage. (Note: the directions of these arrows are very important to engineers, always pay attention to indicate where information is flowing.)

28. 6. Microprocessor Control In this figure the data enters the left side through the inputs. (Note: most engineering diagrams have inputs on the left and outputs on the right.) It travels through buffering circuits before it enters the CPU. The CPU outputs data through other circuits. Memory and disks are used for storage of data that is not destined for output. If we look at a personal computer as a controller, it is controlling the user by outputting stimuli on the screen, and inputting responses from the mouse and the keyboard.

29. 6. Microprocessor Control A PLC is also a computer controlling a process. When fully integrated into an application the analogies become; Inputs the keyboard is analogous to a proximity switch input circuits the serial input chip is like a 24Vdc input card Computer the 686 CPU is like a PLC CPU unit Output circuits a graphics card is like a triac output card Outputs a monitor is like a light Storage memory in PLCs is similar to memories in personal computers It is also possible to implement a PLC using a normal Personal Computer, although this is not advisable. In the case of a PLC the inputs and outputs are designed to be more reliable and rugged for harsh production environments.

30. Regulatory Control

31. 1. Learning Objectives Introduce Regulatory Control. Understanding PID control. Differentiate between various control loops.

32. 2. Introduction Most of the applications of industrial control process used simple loops which regulated flows, temperatures, pressures and levels. Occasionally ratio and cascade control loops could be found. There are many benefits for using regulatory control. One of the most important is simply closer control of the process. Process control is one part of an overall control hierarchy that extends downwards to safety controls and other directly connected process devices, and upward to encompass process optimization and even higher business levels of control such as scheduling, inventory management.

33. 2. Introduction Most control engineers would recognize the form of response. Actually the response could be determined by solving a differential equation. It is more important to have a good understanding of the physical response than to be able to predict the solution by solving the differential equation. Instrumentation, control and process engineers abstract the pictorial form of the process into an iconographic diagram called "Piping and Instrumentation Diagram", i.e. P&ID. For description and analysis of a control loop, without referring to whether it is implemented with analog or digital hardware, a block diagram as shown

34. 3. PID Control 3.1 Feedback Control The principle of feedback is one of the most intuitive concepts known. An action is taken to correct a less satisfactory situation then the results of the action are evaluated. If the situation is not corrected then further action takes place. Feedback control can be classified by the form of the controller output. One of the simplest forms of output is discrete form, also called on-off or two position control. An example of this is the household thermostat, which activates heating unit if the temperature is below the setting, or deactivates the unit if the temperature is above the setting.

35. 3. PID Control 3.1 Feedback Control The idea of two position control can be extended to multi-position control; an example is commercial air-conditioning refrigeration equipment which is operated by loading and unloading compressor cylinders. The ultimate extension is infinite number of positions which is called modulating control; an example is the process controller output that can drive a valve to any position between 0 and 100 percent,

36. 3. PID Control 3.2 Modes of Control Feedback controllers use one, two, or three methods to determine the controller output. These methods, called the modes of control, including the following: Proportional (P) Integral (I) Derivative (D) In general these modes can be used singly or in combination.

37. 3. PID Control 3.2.1 Proportional Mode With a controller containing only the proportional mode, the controller output is proportional to the measurement value only. Neither history of the measurement value nor consideration to the rate of change is utilized. Adjustment , i.e. tuning, of the controller is simple because there is only one adjustment Figure illustrates a proportional control system. The rate of fluid flow into the tank represents the load. To be in equilibrium, the outflow must be the same as the inflow. The outflow is achieved by a particular valve position where the fixed mechanism between the float, pivot and link attain.

38. 3. PID Control 3.2.2 Integral Mode An integrator is the ideal device for automating the procedure for adjusting the controller output bias. It is called the automatic reset. 3.2.3 Derivative Mode The derivative is used to anticipate the effect of load changes by adding a component to the controller output that is proportional to the rate of change of the measurement.

39. 3. PID Control 3.3 Control Loop Structure For microprocessor control system , control strategy is configured by a series of software function blocks. Just like a set of hardware modules require interconnections to form a complete control system, a set of software function blocks also acquire interconnections, i.e. soft-wiring .

40. 3. PID Control 3.3 Control Loop Structure Figure shows a simple feedback loop with the software portion consists of three function blocks: An analog input block that causes the analog to digital converter to convert the incoming 4-20mA signal to an analogous value. The value is deposited in a memory register. A PID control block which obtains the measurement value from the analog input block and compares it with the set point then it executes a PID algorithm to calculate the output. An analog output block that obtains from the PID block the required valve position value. The value is converted by a digital to analog converter to 4-20mA signal.

41. 3. PID Control 3.4 Control Loop Tuning The power of PID control is that by good choice of control parameters the controller can be adjusted to provide the desired behavior on a wide variety of process applications. Determining acceptable values of these parameters is called tuning the controller. A good criterion for acceptable performance is the "quarter cycle decay"

42. 3. PID Control 3.4 Control Loop Tuning Most loops are tuned by experimental techniques, i.e. trial and error. Figures give a tuning map for adjusting control parameters.

43. 4. Control Loop Types 4.1 Ratio Control Figure shows the P&ID of a process heater in which the fuel flow is measured and multiplied by the required air-to-fuel ratio; this results in the required air flow rate, which is introduced as a set point of the feedback controller. The required air-to-fuel ratio is automatically adjusted as the output of the stack O2 controller .

44. 4. Control Loop Types 4.2 Cascade Control Figure the temperature controller cascades a steam flow controller. The temperature controller would react to outlet temperature drop by increasing the set point of the steam flow controller, which in turn would increase the signal to the valve. The flow will quickly respond to increased demand from the temperature controller and thus reaching the desired set point of the outlet temperature stream.

45. 4. Control Loop Types 4.3 Feedforward Control With feedforward control, the objective is to drive the controlling device from a measurement of the disturbance that is affecting the process, rather than from the process variable itself. In figure , the application was analyzed the variation in process inlet temperature was the principle of disturbance. Hence, a feedforward controller is used to drive the fuel flow controller by sensing the inlet temperature.

46. 4. Control Loop Types 4.4 Selector (Override) Control There are several ways of using selector switches in control strategies. One way is to select the higher (or lower) of several measurement signals to pass the process variable to a feedback controller. For example, the highest of several process temperatures may be selected automatically to become the controlling temperature as shown in figure

47. 4. Control Loop Types 4.5 Split Range Control Split range control when one process variable such as plant inlet pressure is used to manage two different output devices such as plant bypass control valve and flow control loop for fractionation area. The 4- 12 mA signal is used to control the flow control loop. If the plant cannot handle all incoming feed, the 12-20 mA signal control the plant bypass valve to direct extra feed to the outside of the plant.

48. DCS Infrastructure

49. 5. DCS Infrastructure 5.1 Learning Objectives Introduce system infrastructure interoperability and interconnectivity. Illustrate system components of level 2 control.

50. 5. DCS Infrastructure

51. 5. DCS Infrastructure 5.2 Communication Bus The communication bus, i.e. the Node-bus , interconnects stations (Control Processors, Application Processors, Application Workstations, and so forth) in the system to form a process management and control node. Depending on application requirements, the node can serve as a single, stand-alone entity, or it can be configured to be part of a more extensive communications network. Operating in conjunction with the Node-bus interface electronics in each station, the Node-bus provides high-speed, redundant, peer-to-peer communications between the stations. The high speed, coupled with the redundancy and peer-to-peer characteristics, provide performance and security superior to that provided by communication media used in conventional computer-based systems. Station interfaces to the Node-bus are also redundant, further ensuring secure communications between the stations. The Node-bus can be implemented in a basic, non-extended configuration or it can be extended through the use of Node-bus Extenders and Dual Node-bus Interface Extenders.

52. 5. DCS Infrastructure 5.2 Communication Bus 5.2.1 Node-bus Interface

53. 5. DCS Infrastructure 5.2 Communication Bus 5.2.1 Node-bus Interface The Node-bus Interface is a module which allows direct connection of a personal workstation (PW), with appropriate Node-bus connector card and software, to the Node-bus . In this configuration, the PW functions as a station on the node. The Node-bus Interface allows connection of a station application workstation hosting an Ethernet configuration to Node-bus . An Attachment Unit Interface ( AUI ) cable, connects the PW or an Ethernet hub configuration to the Node-bus via a Node-bus Interface. A coaxial cable ( Thin-Net ) connects an Ethernet daisy chain configuration to the Node-bus via a Node-bus Extender. The Node-bus Interface is non-redundant, and can be used in any of the Node-bus configurations described.

54. 5. DCS Infrastructure 5.2 Communication Bus 5.2.2 Dual Node-bus Interface The Dual Node-bus Interface ( DNBI ) is a module which allows direct connection of stations to the appropriate Node-bus . Connection between the DNBI and station is made via an AUI cable. For data transmission security, a separate ( RS-423 ) control cable connects between the station and the DNBI to allow switching between the two redundant Node-bus cables. Switching of the Node-bus cables is controlled by the station, which transmits commands to the DNBI via the control cable. Figure shows connection of a station to the Node-bus using a DNBI .

55. 5. DCS Infrastructure 5.2 Communication Bus 5. 2.3 Dual Node-bus Interface Extender The Dual Node-bus Interface Extender ( DNBX ) is functionally similar to the DNBI, but provides a greater cabling distance. The principal transmission medium used is a coaxial Ethernet cable directly connected to the station end by a standard Ethernet transceiver. Figure remote connection of a station to the Node-bus using a DNBX.

56. 5. DCS Infrastructure 5.3 Control Processor The Control Processor performs regulatory, logic, timing, and sequential control together with connected: Fieldbus Modules (FBMs) Fieldbus Cluster I/O Cards (FBCs) It also performs data acquisition ( via the Fieldbus Modules ), alarm detection and notification , and may optionally serve as an interface for one or more Panel Display Stations. The non-fault-tolerant version of the Control Processor is a single-width processor module. The fault-tolerant version consists of two single-width processor modules.

57. 5. DCS Infrastructure 5.3 Control Processor 5.3.1 Enhanced Reliability The Control Processor offers optional fault-tolerance for enhanced reliability. The fault-tolerant control processor configuration consists of two parallel-operating modules with two separate connections to the Node-bus and to the Fieldbus. he two control processor modules, married together as a fault-tolerant pair, are designed to provide continued operation of the unit in the event of virtually any hardware failure occurring within one module of the pair. Both modules receive and process information simultaneously, and the modules themselves detect faults .

58. 5. DCS Infrastructure 5.3 Control Processor 5.3.1 Enhanced Reliability One of the significant methods of fault detection is comparison of communication messages at the module external interfaces. Upon detection of a fault, self-diagnostics are run by both modules to determine which module is defective. The non-defective module then assumes control without affecting normal system operations. To further ensure reliable communications, the fault-tolerant control processor performs error detection and address verification tests in its Node-bus and Fieldbus interfaces. For enhanced reliability during maintenance operations, the Control Processor is equipped with a recessed reset button. This feature provides for manually forcing a module power off and on ( reboot ) without removing the module from the enclosure.

59. 5. DCS Infrastructure 5.3 Control Processor 5.3.2 Diagnostics The Control Processor uses three types of diagnostic tests to detect and/or isolate faults: Power-up self-checks Run-time and watchdog timer checks Off-line diagnostics Power-up self-checks are self-initiated when power is applied to the control processor. These checks perform sequential tests on the various control processor functional elements. Red and green indicators a the front of the control processor module reflect the successful (or non-successful ) completion of the various phases of the control processor startup sequence.

60. 5. DCS Infrastructure 5.3 Control Processor 5.3.2 Diagnostics The run-time and watchdog timer checks provide continuous monitoring of control processor functions during normal system operations. The operator is informed of a malfunction by means of printed or displayed system messages. Off-line diagnostics are temporarily loaded into the system for the purpose of performing comprehensive tests and checks on various system stations and devices. Using the off-line diagnostics, a suspected fault in the control processor can be isolated and/or confirmed.

61. 5. DCS Infrastructure 5.4 Engineering Interface The engineering interface, i.e. Application Processor, is microprocessor-based application processor/file server stations. They perform two basic functions: As application processor ( computer ) stations, they perform computation intensive functions. As file server stations, they process file requests from tasks within themselves or from other stations. Bulk storage devices used with the Application Processors include floppy disk drives, hard disk drives, streaming tape drives, and CD-ROMs .

62. 5. DCS Infrastructure 5.4 Engineering Interface The Application Processors operate in concert with other system stations (such as communication processors, workstation processors, and control processors), which provide the necessary means for data input/output and operator interfacing. A smaller system can utilize a single Application Processor, while a larger system can incorporate several Application Processors, each configured to perform specific functions. Some functions can be performed by individual Application Processors, while others can be shared by two or more Application Processors in the same network. For all models of the Application Processor, applications range from minimal functions, such as the storage of memory images, alarm events, and historical data, to larger-scale applications such as database management and program development.

63. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions System and Network Management Functions The Application Processors perform system management functions, which include collecting system performance statistics, data reconciliation, performing station reloads, providing message broadcasting, handling all station alarms and messages, and maintaining consistent time and date in all system stations. The Application Processor also performs network management functions, which comprise that portion of system management functions which deal with the network.

64. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions System and Network Management Functions The Application Processors perform system management functions, which include collecting system performance statistics, data reconciliation, performing station reloads, providing message broadcasting, handling all station alarms and messages, and maintaining consistent time and date in all system stations. The Application Processor also performs network management functions, which comprise that portion of system management functions which deal with the network.

65. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Database Management Database management involves the storage, manipulation, and retrieval of files containing data received and/or produced by the system. The Application Processors utilize the industry-standard Relational Data Base Management System.

66. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions File Requests Each Application Processor contains a file manager, which manages all file requests associated with bulk memory attached to the Application Processor. Each Application Processor also supports a remote file system that allows tasks in one station to share files in another.

67. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Historical Data The Application Processors can be configured to contain the Historian function, which maintains a history of application messages and continuous and discrete I/O values. These values may represent any parameters such as measurements, set-points, outputs, and status switches from stations that have been configured to collect data and send it to a Historian. In addition, the Historian computes and stores a history of averages, maximums, minimums, and other derived values. This information is maintained for display, reporting, and access by application programs. An archiving facility saves the data on removable media, where applicable. The Application Processors can be configured to maintain a history of errors, alarm conditions, and selected operator actions. The occurrence of errors, alarms, and events in other stations can be stored (for later review and analysis) by sending a message defining the event to the Historian in one or more Application Processors.

68. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Graphic Display Support The Application Processor supports graphic displays by storing and retrieving display formats, by providing access to objects stored on the Application Processor, and by storing tasks which execute in a workstation processor. Application Processors not only provide storage of information and file management for displays, but also execute programs that perform display and trend service.

69. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Production Control Software Production control software represents a large range of packages that require varied Application Processor resources. The following is a list of packages provided: DBMS Historian Spreadsheet Physical Properties Library Mathematics Library BATCH The operation and performance of the production control software are determined by the particular Application Processor configuration.

70. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Configuration Configuration refers to the process of entering or selecting parameters to define what a software package does, or to define the environment for a software package. The Application Processors support configuration functions by providing bulk storage for configuration parameters and by executing some of the configuration processes.

71. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions Application Development Facilities Application development tools are provided to build programs for all system stations. These include tools to document, enter, translate, link, test, and maintain programs written in several programming languages. The Application Processor supports program development for all stations (workstation processors, control processors, and so forth). Assembly language, FORTRAN, and C programs can be written on the Application Processor using standard operating system tools. An optional package is available including text editors, debuggers, linkers, revision control, and compilers, plus execution statistics functions.

72. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.1 Application Processor Functions User Application Program Execution The Application Processors also execute user application programs. These may be application packages such as special optimizations, test data collections, special data reductions, or other packages that you may have already developed. The allocation of resources reserved for user application varies with each Application Processor.

73. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.2 Diagnostics The Application Processors utilize three types of diagnostic tests to detect and/or isolate faults: Power-up self-checks Run-time and watchdog timer checks Off-line diagnostics Power-up self-checks are initiated when power is applied to the Application Processor. These checks perform sequential tests on the various Application Processor functional elements. Any malfunction detected during the power-up self-checks is reported by means of messages printed or displayed on a directly connected printer or terminal.

74. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.2 Diagnostics The run-time and watchdog timer checks provide continuous monitoring of Application Processor functions during normal system operations. For any processor model, you are informed of a malfunction by means of printed or displayed system messages. Off-line diagnostics are temporarily loaded into the system for the purpose of performing comprehensive tests and checks on various system stations and devices. Using the off-line diagnostics, a suspected fault in the Application Processor can be isolated and/or confirmed.

75. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components The workstation components provide user interface to all System CRT display functions. A selection of workstation components is available for command and data entry, along with CRT pointer manipulation and control. These components interact with software resident in versions of the system Workstation Processors ( WPs ) and Application Workstation Processors ( AWs ). Many of these components (displays and keyboards) are " common " and allow interchangeability and simplicity in mixed technology configurations. Workstation components include: -Alphanumeric Keyboard - Annunciator and Annunciator/Numeric Keyboards - Workstation Display (with/without Touchscreen) - Mouse - Trackball - Industrial Pointing Device- Workstation Processor or Application Workstation Processor - Personal Workstation - Modular Industrial Console

76. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Selection of the touch screen, mouse, trackball or industrial pointing device is required for picking display objects on the CRT . The touch screen has sufficient resolution for all functions normally associated with a process operator. Only the mouse or trackball provides the picking resolution necessary for engineer-related functions (for example, building graphic displays). The touch screen associated with Workstation Display and the annunciator type keyboards connects to a Graphics Controller Input Output ( GCIO ) interface unit located beneath the workstation display. The GCIO interfaces to the Workstation Processor and/or Application Workstation that provide secure, high-speed, bidirectional data flow. The alphanumeric keyboard and trackball connect together in a functional grouping via a serial communications link to the processors. Personal Workstations ( PW ) utilize separate serial communication links for alphanumeric keyboard and mouse/trackball. These buses allow a variety of component connections.

77. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Alphanumeric Keyboard The alphanumeric keyboard is used any time text is entered into the system. It consists of the full set of alphanumeric keys plus punctuation and special symbol keys laid out in the standard format, and a numeric data entry pad (with cursor control).

78. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Annunciator Keyboard The Annunciator Keyboard is an array of LED/switch pairs. It also contains a horn silence switch and a lamp-test switch. Each LED, under control of the processor software, may be ON, OFF, or FLASHING as determined by the process conditions. The LEDs, when used in conjunction with the unit's audible annunciator, form an effective means of calling a user's attention to specific areas of the system. The switch associated with each LED can be used to invoke any pre-configured displays or operator responses.

79. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Workstation Display with/without Touchscreen The workstation display is an analog cathode ray tube (CRT) color monitor supporting ultra-high resolution applications. The monitor is suitable for mounting onto a Modular Industrial Workstation or on a desktop. The monitor can include a touchscreen optional feature. Figure shows the monitor with a tilt and swivel base mounted on the GCIO interface unit. The GCIO interface supports the touchscreen, annunciator and annunciator/ numeric keyboard, and audible horn options. The optional touch screen is bonded to the front surface of the CRT monitor. The user selects display objects by touching them on the screen. The touch screen senses the action and sends a data signal to the workstation processor's software indicating the position of the selection.

80. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Trackball The trackball is a stationary component that contains a rotatable sphere. The trackball can be located on a table top. Rotation of the sphere causes CRT pointer movement analogous to the mouse action. Buttons are also provided for user\ selections / manipulations.

81. 5. DCS Infrastructure 5.4 Engineering Interface 5.4.3 Workstation Components Modular Industrial Console Modular Industrial Consoles provide flexible mounting arrangements of components. They allow users to configure centralized or distributed control centers tailored to the functional requirements of each interaction point in the plant. The modular console furniture described herein may incorporate a mix of equipment - console displays, input devices, processors, Fieldbus Modules, data storage devices, and so on. Alternately, only display-specific equipment can be incorporated. Modular Industrial Consoles (MICs) are ideal for supporting powerful multiple-screen, real-time display software interactions. This combination allows console resources to be optimally allocated to meet changing day-to-day needs.

82. 5. DCS Infrastructure 5.4 Engineering Interface 5.5 Operator Interface Operating in conjunction with human interface input/output components, the workstation processors serve as a link between the operator and other distributed processor modules. They receive graphic and textual information both stored internally or from application processors and generate signals to display the information on a workstation display. Display formats and data files are available from bulk storage. Live display information (distributed data objects) is available from any control -processor, or from shared system global data. The video information displayed can include free form combinations of text, graphic illustrations, charts, and control displays. The workstation processors display textual information as 80 text characters per line, with four fonts. The processors provide resizable and restack able windows. Displays for all of the workstation processors may also be developed using the system software running in a compatible personal computer. A workstation processor, together with its workstation monitor and input components, can be configured with combinations of peripherals to suit functions and user preferences.

83. 5. DCS Infrastructure 5.4 Engineering Interface 5.5 Operator Interface The architecture of the DCS permits it to be connected to other foreign systems using a gateway module for adapting different communication protocols.

84. DCS Hardware

85. 6. DCS Hardware 6.1 Learning Objectives Define fieldbus communication. Illustrate system components of level 1 control. Demonstrate interconnection between different components. Develop knowledge base of foundation fieldbus technology.

86. 6. DCS Hardware 6.2 Fieldbus Modules Fieldbus Modules provide connection of digital I/O, analog I/O, and Intelligent Transmitters to control processors. There are two types of Fieldbus Modules: Main and Expansion. Some main modules can be expanded using an expansion module. A wide range of Fieldbus Modules is available to perform the signal conversion necessary to interface the control processor with field sensors and actuators.

87. 6. DCS Hardware 6.3 Fieldbus Interconnection The Control Processor is used in three different configurations, which provide broad flexibility in Fieldbus implementation: Local Fieldbus Figure - Used only within the enclosure. Fieldbus Modules attach directly to the redundant local bus.

88. 6. DCS Hardware 6.3 Fieldbus Interconnection Twin-axial (Dual-Conductor Coaxial) Fieldbus Extension (Figure) - Using twin-axial cable, the Fieldbus can optionally extend outside of the enclosure. Fieldbus Modules attach to the extended bus through Fieldbus isolators. The twin-axial Fieldbus extension may be redundant.

89. 6. DCS Hardware 6.3 Fieldbus Interconnection Fiber Optic Fieldbus Extension (Figure) - The fiber optic Fieldbus can optionally extend the distance as well as add application versatility and security. All three Fieldbus configurations use serial data communication complying with Electronic Industrial Association (EIA) Standard RS-485.

90. 6. DCS Hardware 6. 4 Cluster I/O Sub-system Interfacing The Control Processor interfaces with the Fieldbus Cluster Input/output Subsystem that consists of the Fieldbus, a multi-slot chassis configuration of a Fieldbus Processor, analog/digital Fieldbus Cards (FBCs), and power supply and power monitor card. These Cluster I/O subsystems meet the needs of applications where a high number of channels per card are required. Figure shows a typical twin-axial Fieldbus configuration.

91. 6. DCS Hardware 6. 5 Fieldbus Cluster I/O Subsystem The Fieldbus Cluster Input/output Subsystem provides full support for analog measurement, digital sensing, and analog or discrete control capabilities. The Subsystem integrates with the Control Processor or Personal Workstation via the Fieldbus, and includes a multi-slot chassis configuration made up of a Fieldbus Processor, Analog/Digital Fieldbus Cards (FBC), subsystem main power supply, and power monitor card. The Fieldbus Cluster I/O Subsystem is configurable, gathering analog measurements, while simultaneously handling analog and digital input and output channels. The Fieldbus Cluster I/O Subsystem is offered in both non-redundant and redundant configurations. Each in a redundant pair is individually addressable on the Fieldbus with a unique logical address. In a redundant configuration, the FBPs provide switchover from the primary FBP to the redundant FBP and back again automatically. The FBCs are suitable in applications where a high number of channels per card are required. They are ideal for non-isolated and isolated input signal gathering and data acquisition systems where high quantities of "points per cluster" areas are desired.

92. 6. DCS Hardware 6.5 Fieldbus Cluster I/O Subsystem The FBCs may be optionally connected as redundant pairs. Various input cards are available with one of the following three levels of isolation: Non-isolated - Each channel is referenced to ground and the card itself is referenced to ground. Group-isolated - Electrically separate card-to-card but not channel-to-channel on the same card. Isolated - Each channel is electrically separated from any other channel, card, group, building, site, etc.

93. 6. DCS Hardware 6.6 Fieldbus Processor The Fieldbus Processor (FBP) module provides communication between the Fieldbus Cards (FBCs) and the Control Processor. Optionally available is redundancy for the FBP module. Each FBP module is individually addressable via the Fieldbus. If the primary FBP fails or is taken off-line, the secondary FBP automatically assumes control. It remains in control until the primary FBP returns on-line (figure).

94. 6. DCS Hardware 6.7 Fieldbus Cards The Fieldbus Cards support a variety of analog and digital I/O signals. The FBCs convert electrical I/O signals used by field devices to permit communication with these devices via the Fieldbus. The FBCs can be connected in a redundant configuration via the hardware. The redundant FBCs must be in adjacent slots and they are connected via a hardware adapter at the interface to the field devices. In an FBC redundant configuration, the FBP determines which FBC of the redundant pair is to supply the data to the Control Processor. This is done in the software by a predetermined set of conditions.

95. 6. DCS Hardware 6.7 Fieldbus Cards 6.7.1 Analog FBCS The analog FBCs support analog signal types and control functions equipped with accurate signal conditioning circuitry, the analog cards interface between process sensors and actuators. To input an analog voltage (into DCS) the continuous voltage value must be sampled and then converted to a numerical value by an A/D converter. Figure shows a continuous voltage changing over time. There are three samples shown on the figure. The process of sampling the data is not instantaneous, so each sample has a start and stop time. The time required to acquire the sample is called the sampling time. A/D converters can only acquire a limited number of samples per second. The time between samples is called the sampling period T, and the inverse of the sampling period is the sampling frequency (also called sampling rate). The sampling time is often much smaller than the sampling period.

96. 6. DCS Hardware 6.7 Fieldbus Cards 6.7.1 Analog FBCS Analog outputs are much simpler than analog inputs. To set an analog output an integer is converted to a voltage. This process is very fast, and does not experience the timing problems with analog inputs. But, analog outputs are subject to quantization errors. Figure gives a summary of the important relationships. These relationships are almost identical to those of the A/D converter. Assume we are using an 8 bit D/A converter that outputs values between 0V and 10V. We have a resolution of 256, where 0 results in an output of 0V and 255 results in 10V. The quantization error will be 20mV. If we want to output a voltage of 6.234V, we would specify an output integer of 159, this would result in an output voltage of 6.235V. The quantization error would be 6.235V-6.234V=0.001V. The current output from a D/A converter is normally limited to a small value, typically less than 20mA.

97. 6. DCS Hardware 6.7 Fieldbus Cards 6.7.2 Digital FBCS The digital FBCs consist of 32- and 64-channel types. Inputs can be either voltage monitoring or contact sensing. Contact inputs must convert a variety of logic levels to the 5Vdc logic levels used on the data bus. This can be done with circuits similar to figure 4.8. Basically the circuits condition the input to drive an opto -coupler. This electrically isolates the external electrical circuitry from the internal circuitry. Other circuit components are used to guard against excess or reversed voltage polarity. Contact outputs must convert the 5Vdc logic levels on the DCS data bus to external voltage levels. This can be done with circuits similar to figure. Basically the circuits use an opto -coupler to switch external circuitry. This electrically isolates the external electrical circuitry from the internal circuitry. Other circuit components are used to guard against excess or reversed voltage polarity.

98. 6. DCS Hardware 6.7 Fieldbus Cards 6.8 Other Modules 0 to 20 mA Input/output Interface Pulse Input, 0 to 20 mA Output Interface Thermocouple/ Millivolt Input Interface RTD Input Interface High Power Contact/dc Input/output Interface

99. 6. DCS Hardware 6.8 Other Modules 0 to 20 mA Input/output Interface Pulse Input, 0 to 20 mA Output Interface Thermocouple/ Millivolt Input Interface RTD Input Interface High Power Contact/dc Input/output Interface

100. 6. DCS Hardware 6.9 Foundation Fieldbus Technology FOUNDATION fieldbus is an all-digital, serial, two-way communications system that serves as the base-level network in a plant or factory automation environment.

101. 6. DCS Hardware 6.9 Foundation Fieldbus Technology It's ideal for applications using basic and advanced regulatory control, and for much of the discrete control associated with those functions. Two related implementations of FOUNDATION fieldbus have been introduced to meet different needs within the process automation environment. These two implementations use different physical media and communication speeds. H1 works at 31.25 Kbit/sec and generally connects to field devices. It provides communication and power over standard twisted-pair wiring. H1 is currently the most common implementation and is therefore the focus of these courses. HSE (High-speed Ethernet) works at 100 Mbit/sec and generally connects input/output subsystems, host systems, linking devices, gateways, and field devices using standard Ethernet cabling. It doesn't currently provide power over the cable, although work is under way to address this.

102. 6. DCS Hardware 6.9 Foundation Fieldbus Technology conventional analog and discrete field instruments use point-to-point wiring: one wire pair per device. They're also limited to carrying only one piece of information -- usually a process variable or control output -- over those wires. As a digital bus, FOUNDATION fieldbus doesn't have those limitations. Multidrop wiring. FOUNDATION fieldbus will support up to 32 devices on a single pair of wires (called a segment) -- more if repeaters are used. In actual practice, considerations such as power, process modularity, and loop execution speed make 4 to 16 devices per H1 segment more typical. That means if you have 1000 devices -- which would require 1000 wire pairs with traditional technology -- you only need 60 to 250 wire pairs with FOUNDATION fieldbus. That's a lot of savings in wiring (and wiring installation).

103. 6. DCS Hardware 6.9 Foundation Fieldbus Technology Multivariable instruments. That same wire pair can handle multiple variables from one field device. For example, one temperature transmitter might communicate inputs from as many as eight sensors -- reducing both wiring and instrument costs. Other benefits of reducing several devices to one can include fewer pipe penetrations and lower engineering costs. Two-way communication . In addition, the information flow can now be two-way. A valve controller can accept a control output from a host system or other source and send back the actual valve position for more precise control. In an analog world, that would take another pair of wires. New types of information. Traditional analog and discrete devices have no way to tell you if they're operating correctly, or if the process information they're sending is valid.

104. 6. DCS Hardware 6.9 Foundation Fieldbus Technology But FOUNDATION fieldbus devices can tell you if they're operating correctly, and if the information they're sending is good, bad, or uncertain. This eliminates the need for most routine checks -- and helps you detect failure conditions before they cause a major process problem. Control in the field. FOUNDATION fieldbus also offers the option of executing some or all control algorithms in field devices rather than a central host system. Depending on the application, control in the field may provide lower costs and better performance -- while enabling automatic control to continue even if there's a host-related failure.

105. 6. DCS Hardware 6.9 Foundation Fieldbus Technology FOUNDATION fieldbus is covered by standards from three major organizations: ANSI/ISA 50.02 IEC 61158 CENELEC EN50170:1996/A1 The technology is managed by the independent, not-for-profit Fieldbus Foundation, whose 150+ member companies include users as well as all major process automation suppliers around the globe. Some suppliers have even donated fieldbus-related patents to the Fieldbus Foundation to encourage wider use of the technology by all Foundation members. Interoperability simply means that FOUNDATION fieldbus devices and host systems can work together while giving you the full functionality of each component.

106. DCS Software

107. 7. DCS Software 7.1 Learning objectives To be familiar with main software components of DCS. Understand main tasks for each application.

108. 7. DCS Software 7.2 Standard Application Packages 7.2.1 System Management Features include: Display of equipment information for the station and its associated input/output devices, buses, and printers. Capability for change actions directed to the associated equipment. Processing of station alarm conditions and messages. 7.2.2 Database Management Features include: Storage, retrieval, and manipulation of system data files. A run-time license for the embedded use of the Relational Database Management System. A spreadsheet package.

109. 7. DCS Software 7.2 Standard Application Packages 7.2.3 Historian Features include: Maintenance of a history of values for process-related measurements that have been configured for retention by the Historian. Maintenance of a history of application messages that have been sent to the Historian. Maintenance of a history of alarms and error conditions which generate messages for the Historian. Access to all Historian data by display and report application programs.

110. 7. DCS Software 7.2 Standard Application Packages 7.2.4 View Display Manager Features include: Presentation of the operating environment. Setting of the overall operating environment according to the type of user. Process engineers, process operators, and software engineers have access to specialized functions and databases suited to their specific requirements and authorizations. Dynamic and interactive process graphics. Display and processing of current process alarms. Group and default displays for control blocks. Execution of embedded trending within displays.

111. 7. DCS Software 7.2 Standard Application Packages 7.2.5 Draw Display Builder Features include: Graphical display configuration for viewing and control of process operation. Access to graphical object palettes allowing easy inclusion of pumps, tanks, valves, ISA symbols, and similar complex objects. Ready modification of existing displays using a mouse pointer, menu items, and quick-access toolbars. Association of process variables with objects in the displays. Dynamic variation of object attributes such as fill level, color, position, size and visibility with changes in the associated process variable. Inclusion of operator control elements such as pushbuttons and sliders into displays. A library of faceplates which may be configured by simply specifying the compound and block name of the block to which the faceplate is to be connected.

112. 7. DCS Software 7.3 Alarm System

113. 7. DCS Software 7.3 Alarm System Alarm Manager provides an easy-to-use graphical interface of preconfigured alarm displays for viewing and quickly responding to process alarm conditions. The alarm display windows present alarm messages initiated by the control blocks and related to digital input, state change, absolute analog, deviation, rate of change, device status mismatch, and other alarm conditions.

114. 7. DCS Software 7.3 Alarm System Accessible from any environment, the Alarm Manager Display windows provide: Quick, easy access to the most recent alarm messages via the Most Recent Alarm display or Current Alarm display Alarm status and value information dynamically updated from the control station Color-coded priority and status indicators that allow you to quickly focus in on critical alarms Summary displays for different views of the alarm database based on alarm status An historical list of alarms The capability to view subsets of alarms based on specific user-defined criteria The capability to silence or temporarily mute workstation and annunciator horns. Secured access to alarming functions dependent on user or system responsibility

115. 7. DCS Software 7.3 Alarm System This set of resizable alarm displays providing a variety of current and historic views of the process alarm database includes: A multi-page list of all the current alarms A single page of the most recent, active, unacknowledged alarms with dynamically updating value and status fields Three summary displays specific to alarm status also with updating values and statuses: All active, unacknowledged alarms All unacknowledged alarms that have returned to normal All active, acknowledged alarms A list of historical alarms related to the selected historian database An operations display for silencing horns, temporarily muting horns, changing environments

116. 7. DCS Software 7.3 Alarm System These displays allow you to respond to alarm conditions, filter and analyze specific alarm data, and maintain alarm message files for reporting purposes. The Process or Alarm button in the Display Manager ( DM ) window indicates the presence of alarms ( both acknowledged and unacknowledged ) and provides access to Alarm Manager Displays. Initially, the Current Alarm Display ( CAD ) appears and the other displays are easily accessible from the CAD via its default Displays menu: Most Recent Alarm display ( MRA ) New Alarm display ( NEWALM ) Unacknowledged Alarms display ( UNACK ) Acknowledged Alarms display ( ACKALM ) Alarm History display ( AHD ) Operations display ( OPR )

117. 7. DCS Software 7.3 Alarm System These easy-to-use displays support the following features : A pre-configured number of alarms per screen or page Pre-configured alarm message information and formatting per alarm type A status area for indication of current Alarm Manager and display status, such as horns muted, match active, display paused, initial call-up time Buttons for responding to alarm conditions, such as acknowledging or clearing alarms, and for accessing additional alarm information and process displays Pull-down menus for editing, viewing, and filing functions A pull-down menu for accessing other displays Pop-up menus for quick access to commonly used functions A scroll bar and Go To Page option for moving easily through the alarm list Although a preconfigured set of alarm displays is provided, many aspects of the displays and alarm message content are user configurable to accommodate different process control applications and operational needs. See the section on Alarm/Display Manager Configurator.

118. 7. DCS Software 7.4 Historian The Historian collects , stores , processes , and archives process data from the control system to provide data for trends, Statistical Process Control ( SPC ) charts, logs, reports, spreadsheets, and application programs. The Historian software is an easy-to-use data collection tool that allows the user to organize and enforce a plant data collection philosophy. The Historian provides extensive data collection and management functions, and data display functions for use by process engineers or operators. Typical historical data are process analog and/or digital variables (points). The Historian can also collect and display application generated messages.

119. 7. DCS Software 7.4 Historian You can use the Historian to collect data in support of the following production control functions: Cost accounting Equipment performance analysis Historical trending Information retrieval Inventory management Legal record maintenance Lost time analysis Maintenance reporting Material accounting Process analysis Production reporting Quality control

120. 7. DCS Software 7.4 Historian The Historian can: Retrieve variables from process databases or accept data from production control databases maintained by user application programs. Perform built-in calculations on the collected data. Store calculated (reduced) data in a real time, relational database. Application software in a plant-wide control system can access the Historian database to obtain historical data for process control, production control, and management information reporting. You can use SPC chart displays of Historian data to monitor process variables on-line via the Statistical Process Control Package ( SPCP ). You can build displays for trending historical data via the Display Builder and Display Configurator with Trending software. Using the Report Writer, you can generate detailed reports of historical data for management information.

121. 7. DCS Software 7.4 Historian Examples of Industrial Software that interface with the Historian are: Batch Plant Management Data Validator Display Manager Display Configurator with Trending Object Manager (for process data histories) Operator Action Journal Operator Message Interface Real-Time Data Base Manager Spreadsheet Statistical Process Control Package System Monitor Report Writer

122. 7. DCS Software 7.5 Draw

123. 7. DCS Software 7.5 Draw Draw is a display builder and configurator that allow you to create and maintain dynamically updating process displays. Displays can represent the plant, a process area or a detailed portion of the process. You can draw basic objects using Draw's toolbars, menu items and shortcut keys. You assign graphic attributes such as color and line style to the objects, and then configure them to reflect process variable changes or operator actions. Draw includes numerous palettes of objects such as operator buttons, pumps, tanks, pipes, motors, valves and ISA symbols. You can also create your own palettes for storing complex objects and company-standard symbols. Displays can include faceplates, trends and bitmapped images. You can easily edit your displays to reflect changes in the process control scheme or to maximize operating efficiency and security.

124. 7. DCS Software 7.5 Draw 7.5.1 Configuration There are two ways of configuring a display object. You can: 1. Choose the Dynamic Update tab to connect one of the object's attributes, such as visibility or fill level, to a process variable or a file. With this type of configuration, changes in an attribute are triggered dynamically by changes in the process variable. No operator intervention is necessary. 2. Choose the Operator Action tab to connect the entire object to an action, such as opening a display or executing a command. An operator triggers the action by selecting the object. An individual object can have both types of connections, although it can have only one operator action.

125. 7. DCS Software 7.5 Draw 7.5.2 Operator Actions In a display configured for operator action, an operator can trigger events by selecting an object (typically a button), moving a slider, or typing text or a numeric value. In response to an operator action, variables can be modified, a new display can open or an overlay can appear. While you can configure only one operator action for each display object, you can trigger two or more events with a single operator action by configuring an object with a View display command script. Operator Actions include: Open Display Open Overlay Close Display/Overlay Display Command Relative Pick Momentary Contact Ramp Connect Variable Move Horizontal or Vertical Numeric/Text Entry

126. 7. DCS Software 7.5 Draw 7.5.3 Faceplates A faceplate is a dynamic representation of control block parameters. Draw provides a complete library of faceplates, ready to be connected to any control block in the control database. In addition, you can build your own faceplates using the standard Draw drawing tools. To configure a faceplate, you need only define the Compound: block to which the faceplate is connected. Draw automatically determines the proper configuration attributes for the associated Compound: block.

127. 7. DCS Software 7.5 Draw 7.5.3 Faceplates A faceplate is a dynamic representation of control block parameters. Draw provides a complete library of faceplates, ready to be connected to any control block in the control database. In addition, you can build your own faceplates using the standard Draw drawing tools. To configure a faceplate, you need only define the Compound: block to which the faceplate is connected. Draw automatically determines the proper configuration attributes for the associated Compound: block. 7.5.4 Trends Trend areas represent changing data values from the real-time database and historian database. A data is displayed as a series of plotted points connected by straight lines and scaled according to the high and low limits configured for each trend line. 7.5.5 Group Displays Group displays allow you to group faceplates and trends into unique layouts to meet changing operational needs.

128. 7. DCS Software 7.6 View

129. 7. DCS Software 7.6 View View is a window into the system software, providing a user-friendly interface to the total process. You can interact with any or all of the real-time plant, field, and process data available in the system. View provides: Direct access to dynamic process displays. Entry into user-configurable operating environments specific to each user - the process engineer, process operator, and software engineer. Execution of embedded real-time and historical trending. Service and display of process alarms via the Alarm Manager. An overview of the compounds and blocks in the control database and access to block default detail displays via Select.

130. 7. DCS Software 7.6 View Access to other applications, such as: Draw software for building and configuring dynamic user graphics. System Management Displays for monitoring system equipment health. Integrated Control Configurator for configuring the control database. Historian for configuring the historization of data and system messages. Access to the four most recently used displays. Additionally, with View you have: Flexibility in customizing environments to conform to your site requirements.  Rapid access to View while in other applications. Screen print utility. Window sizing options. The multi-window capability of Solaris and Windows NT operating systems allows you to monitor the information on a process control display as well as access other applications without closing any window.

131. 7. DCS Software 7.6 View 7.6.1 View Window View Window contains the following features: A top menu bar for accessing displays, configurators, and other applications as specified by the environment. A display bar of named display buttons or eight "thumbnail" mini-display buttons for directly accessing process displays. A system bar with System and Process alarm buttons indicating system and process health; a message bar with a dropdown list of the latest messages; display of the current date and time. A status bar indicating the current display name, current operating environment, Operator Action Journal logging name, printer logging name, Historian name. Using the control window menu, you can: Resize the View window automatically or manually. Move the window.

132. 7. DCS Software 7.6 View 7.6.2 Operating Environments A collection of programs, utilities, and displays related to user tasks is provided for each of the following: process operator, process engineer, and software engineer . These environments, including menu bars, menu content, and Display Bar content, can be modified to conform to your site requirements. You can easily switch from one configured environment to another. To secure environments against unauthorized use, environment passwords can be configured and menu entries disabled based on the environment.

133. 7. DCS Software 7.7 Operator Action Journal The Operator Action Journal is a record of specific operator actions taken during process control operations. These actions generally consist of manipulating certain Control Processor, and gateway parameters as well as Application Processor, Application Workstation, and Workstation Processor shared variables. Actions of this type are the ramping or direct data entry of point values, toggling points, changing block statuses, acknowledging block alarms, and horn muting. Operator action reporting is limited to operator actions from the Display Manager, View, and Alarm Manager. Also logged are environment change actions, scripts, applics , and invoking other applications such as configuration. When the Operator Action Journal feature is enabled, all operator actions within the Display Manager, View, and the Alarm Manager that change parameters in the process database are logged to a printer and/or to the specified Historian database. These operator actions include toggling points, ramping or direct data entry of new point values, changing block statuses, acknowledging block alarms, and other actions such as horn muting.

134. 7. DCS Software 7.7 Operator Action Journal Information logged as a result of each database change includes: Name of the Display Manager, FoxView , or Alarm Manager that requested the database change. Compound:Block.Point for which the change was made. The "old value" TO "new value" text for non-packed Boolean. Current mask and data value for packed Boolean/long. Following is an example of an Operator Action Journal Report. Operator Action Journal Report Tue Aug 1 1997 17:04:05 Page 1 08-02-97 07:57:08 GC3E31 SCRIPT / usr /fox/hi/ init.cmds 08-02-97 07:57:15 GC3E31 ChgEnv Init_Env -> Init_env 08-02-97 07:58:19 GC3E31 ChgEnv Init+Env -> Proc_Eng_Env 08-02-97 08:00:34 CG3E31 UC01_LEAD :SINE .OUT 16.18 to 46.18 08-02-97 08:00:54 GC3E31 UC01_LEAD :SINE .MA Manual to Auto 08-02-97 08:00:57 GC3E31 UC01_LEAD :SINE .LR Remote to Local 08-02-97 08:01:01 GC3E31 UC01_LEAD :SINE .MA Auto to Manual

135. 7. DCS Software 7.8 Control Configuration Process control for DCS is based on the concepts of compounds and blocks. A compound is a logical collection of blocks that performs a control strategy. A block is a member of a set of algorithms that performs a certain control task within the compound structure. Figure shows the compound/block relationship. The compound provides the basis for the integration of: Continuous control Ladder logic Sequential control. Within this structure, any block in any compound can be connected to any other block in any other compound in the system. The entire compound structure can be viewed through the workstation display. The block contains parameters that have values of the types: Real, Boolean, Packed Boolean, Boolean Long, Integer, or String.

136. 7. DCS Software 7.8 Control Configuration 7.8.1 Compound Functions The compound supports the following functions for the related blocks: Process alarm priority, alarm inhibiting, and alarm grouping Sequence status notification (see Sequential Control section) Phasing for execution load leveling at execution time. 7.8.2 Compound/Block Process Alarming Alarms and status messages are generated by specific alarm blocks and by alarm options in selected blocks. Alarms have five levels of priority, 1-5 , ( where 1 = highest priority ) that enable you to quickly focus on the most important plant alarm conditions. An alarm priority of 0 indicates the absence of any alarm. These are summarized in a single alarm summary parameter for each compound. This parameter contains the priority of the highest current alarm in that compound. To reduce nuisance alarms, alarms can be inhibited at the compound level on a priority level basis. Alarms can also be inhibited at the block level, on either an alarm type basis, or an overall basis.

137. 7. DCS Software 7.8 Control Configuration 7.8.3 Compound/Block Phasing A user-defined phase number can be assigned to each compound using a range of integer values that varies with assigned period. Phasing allows the starting time of one compound/block to lead or lag the starting time of another compound/block, thereby leveling the block processor load. 7.8.4 Compound Attributes The compound has the following attributes: Name : User-defined name that must be system-unique and no more than 12 characters in length. The name can be any mix of numeric ( 0 to 9 ), upper case alphabetic ( A to Z ), and the underscore ( _ ). Descriptor : 32-character field for user-defined identification. On/Off : Parameter that enables or disables the execution of all blocks within the compound, where: 1 = on; 0 = off .

138. 7. DCS Software 7.8 Control Configuration 7.8.5 Compound/Block Parameters Compound and block parameters contain values that are of one of the types Real, String, Integer, Short Integer, Long Integer, Boolean, Packed Boolean, Packed Long, or Character. Additionally, parameters are defined as being configurable, and either connectable/settable, not connectable/not settable, or a combination that is dependent upon the compound, block, and state. 7.8.5.1 Configurable Parameters Configurable parameters are those parameters that can be defined through the Integrated Control Configurator. They can be displayable only, or displayable and editable.

139. 7. DCS Software 7.8 Control Configuration 7.8.5 Compound/Block Parameters 7.8.5.2 Connectable Parameters Connectable parameters are those parameters of the user interface in which secured, change-driven connections may be made between network stations, or as local direct connections within the same station. Each connection consists of a connectable source and a connectable sink. Output parameters (all outputs are connectable) are sources, while a connectable input may be a sink or a source, or both. Certain parameters that may be considered functional inputs (such as SPT in the PID blocks, and RATIO in the RATIO block) are settable but not connectable. A connectable parameter has a value record that contains the parameter's value, its status, and its designated value type (Real, Boolean, or Integer).

140. 7. DCS Software 7.8 Control Configuration 7.8.5 Compound/Block Parameters 7.8.5.3 Input Parameters Input parameters are connectable types that are the receivers of data from other connectable parameters via a path connection. If no source path is specified during configuration, then the resident data of the value record is the actual " source " of data. It can be either the initial default or configured value, or a new value through a SET call to the input parameter. If a source path is specified, then the data value is an output parameter of the same or another block, or a shared variable, thereby securing the input. By linking a shared variable to a block input during configuration, the user can establish a long-term secured connection between a remote application program and the block input.

141. 7. DCS Software 7.8 Control Configuration 7.8.5 Compound/Block Parameters 7.8.5.4 Output Parameters All output parameters are connectable data sources that have value records. There are two types: settable and nonsettable. The settability of a settable output is controlled by the secured status of the value record. The secured status is dependent on whether the block's operational mode is in Auto or in Manual. In either Auto or Manual, no settable output parameters cannot be written by any other source under any conditions. Settable outputs may be conditionally released by the block algorithm in the Manual mode. In Manual, the block un secures settable output parameters. They can then be written by other tasks via SET calls. When the block switches to Auto, the block secures and updates its output parameter(s).

142. 7. DCS Software 7.8 Control Configuration 7.8.5 Compound/Block Parameters 7.8.5.5 Nonconnectable Parameters Nonconnectable parameters have no value records and are not linkable. They mainly consist of string-type variables like NAME, or nonsettable parameters that are used in the configurator only, for example, block options. Local algorithm variables are also nonconnectable. Nonconnectable parameters are generally accessible through GET calls. There is also a class of nonconnectable input parameters that comprise the block user interface which can be manipulated through SET calls. An example is an alarm deadband.

143. Installation

144. 8. Installation 8.1 Learning objectives To be able to define installation procedure for each component.

145. 8. Installation 8.2 Modular Industrial Console The Modular Industrial Console ( MIC ) provides flexible mounting arrangements for components. The MIC can incorporate a mixture of equipment: console displays, input devices, processors, Fieldbus modules, data storage devices, and so on. Modular Industrial Consoles support powerful multiple-screen, real-time display software interactions. This hardware/software combination allows console resources to be allocated with the flexibility to meet changing day-to-day needs. Multi-screen consoles enable comprehensive handling of more plant information in a coordinated fashion. procedure for each component.

146. 8. Installation 8.2 Modular Industrial Console The MIC product line (Figure) allows a highly flexible packaging configuration of console equipment. Individual MIC modules are joined on-site to provide a customized configuration using standard components. This modular approach offers you combinations of single-screen and multi-screen real-time display software interactions as required at a given console. There are, however, specific allocations for mounting equipment within configurations. The MIC is built up from four basic pieces of equipment, each of which is individually configurable: MIC bay - basic full bay unit, full height, 27-inches wide, with bay module Spacer module - storage space between MIC full bay units Desktop/printer bay - a rear bay similar to the full bay unit's with a flat tabletop Free standing table - a basic multipurpose table.

147. 8. Installation 8.3 System Equipment 8.3.1 Unloading The system units must be designed to withstand vibration and shock normally encountered during shipping and installation; however, extreme shocks and vibration should be avoided. The system units may be moved from the transportation vehicle to their intended locations by forklift or manual jack truck. If practical, all major movements of the units should be accomplished before the units are unpacked.

148. 8. Installation 8.3 System Equipment 8.3.2 Unpacking Procedure The following unpacking procedure applies, in general, to all system units: Inspect the exterior of the shipping carton for obvious damage. (Any noticeable damage should be indicated in the shipper's bill of lading.) Verify that the equipment received is that described in the bill of lading. Remove shipping straps, shipping shroud, and other packing materials, such as polyethylene bags and Styrofoam cushioning materials. If the unit is attached to a skid, remove all shipping hardware and hold-down bolts used to fasten the unit to the skid. Separate the skid from the unit. Ensure that the appropriate interconnecting cables are present, by comparing the cable part numbers and quantities with those listed in the bill of lading.

149. 8. Installation 8.3 System Equipment 8.3.3 System Power Checks Perform the following checks before you install the equipment: Check that all the required ac or dc power distribution network lines are installed. Check that the appropriate number of ac power outlets are installed and spaced appropriately. Switch on main system power. Using a multi-meter, check that the appropriate operating voltage exists at each ac outlet or connection point. Switch off main system power.

150. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures

151. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures Figure shows a single dual-height modular mounting structure area for containing processors and modules in an Industrial Enclosure. Enclosures are designed for floor mounting, and accept processor modules, Fieldbus modules, and data storage devices. Wires, cables, and conduits can enter either the bottom or the top of the enclosure. Side doors provide access to the wiring areas. Additionally, the doors can be mounted to open from left-to-right or right-to-left. Industrial Enclosures are available in two configurations, vented and sealed. The vented configuration has openings at the top and bottom to provide ventilation, and has a metal plate, with gasket, at the bottom for electrical protection purposes.

152. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 1. Check that mounting holes have been drilled in floor. If they have not, proceed as follows. ( If below-floor cabling is to be employed, refer to the Site Planning document for information on the recommended size and placement of the floor cutout.) a. Place enclosure in desired location. b. Mark hole locations. c. Move the enclosure away from the markings. d. Drill holes in floor.

153. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 2. If the enclosure is the vented type and conduit entry is to be from the bottom: a. Drill or punch the bottom conduit enclosure plate, and provide appropriate conduit fittings. b. Place the conduit enclosure plate on the floor, in the precise location that the enclosure is to be mounted. c. Go to Step 6.

154. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 3. If the enclosure is the vented type, and conduit entry is to be from the top: a. Remove the vent cap and top conduit enclosure plate(s). b. Drill or punch the conduit enclosure plate(s). c. Replace the vent cap and conduit enclosure plate(s). d. Place the enclosure plate on the floor, in the precise location that the enclosure is to be mounted. e. Go to Step 6.

155. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 4. If the enclosure is the sealed type and conduit entry is to be from the bottom: a. Drill or punch the bottom conduit enclosure plate, and provide appropriate conduit fittings for a watertight seal. b. Place the conduit enclosure plate on the floor, in the precise location that the enclosure will be mounted. c. Go to Step 6.

156. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 5. If the enclosure is the sealed type and conduit entry is to be from the top: a. Remove the top conduit enclosure plate. b. Drill or punch the conduit enclosure plate, and provide appropriate conduit fittings for a watertight seal. c. Replace the conduit enclosure plate.

157. 8. Installation 8.3 System Equipment 8.3.4 Industrial Enclosures Mounting Procedures A sealed enclosure has metal plates, with gaskets, at the top and bottom to provide a watertight seal. 6. Position the enclosure , with mounting gasket and enclosure plate, so that the holes in the enclosure base, gasket, and enclosure plate are aligned with the mounting holes in the floor. 7. Install two bolts , with flat washers and lockwashers , in diagonally opposite mounting holes. (Do not tighten.) 8. Install two more bolts , with flat washers and lockwashers , in the other two diagonally opposite mounting holes. (Do not tighten.) 9. Install the remaining bolts , with flat washers and lockwashers , in the center mounting holes. 10.Tighten all bolts evenly and equally , working from center to outside bolts, being careful not to overtighten. Maximum torque should be applied carefully.

158. 8. Installation 8.4 Software Installation The Installation Phase performs the installation of software packages. Installation of software packages is performed by vendor representative on target stations. 8.5 Discussion Initiate a dialogue between trainees to discuss their own experiences and notes about different installation phases related to the text in this chapter.

159. Maintenance

160. 9. Maintenance 9.1 Learning objectives Understand maintenance philosophy and procedures.

161. 9. Maintenance 9.2 Maintenance Philosophy The maintenance approach is oriented toward module replacement. The use of diagnostics, fault location tables, and troubleshooting guides described in system document, as well as the presence of status lamps ( LEDs ) on each module, enables isolation of problems to the module level. In addition , any module can be replaced without affecting the operation of any other module, including the module of a fault-tolerant pair.

162. 9. Maintenance 9.3 Preventive Maintenance The design of DCS equipment and associated peripheral devices is such that scheduled preventive maintenance on the equipment is limited to visual inspections, periodic cleaning procedures, and adjustment of system modules if necessary. While performing these routines, you should check for damaged cables, loose connections, inoperative fans and indicator lamps, wear or binding of drives and fan motors, and take appropriate corrective action.

163. 9. Maintenance 9.3 Preventive Maintenance 9.3.1 Enclosures Perform a general visual inspection and exterior cleaning of each enclosure after the first six months of service. Approximately every 12 months thereafter perform the same, depending on local environmental conditions. Preventive maintenance procedures for enclosures include the following: 1. Wipe down the exterior of the enclosure with a soft cloth. A damp cloth and/or a nonabrasive cleaner can be used for hard-to-remove spots. 2. Clean any dust buildup from module heat fins. Use a soft cloth. If heat fins are accessible from rear of enclosure, they can be cleaned during normal operation. Otherwise, modules can be removed and cleaned from front of enclosure during routine equipment shutdowns. 3. Check fans (if installed) for proper operation. 4. Check module status indicators for proper operation. Green light indicates normal operation. Red light indicates faulty operation.

164. 9. Maintenance 9.3 Preventive Maintenance 9.3.2 Enclosures Air Filters The vented configurations of all metal enclosures have an air filter located inside the door, behind the vents. Periodically check the condition of the filter for dust/dirt accumulation. Perform the following steps to check the condition of the filter: 1. Locate the plastic assembly that retains the filter that is on the inside of the door behind the vents. 2. Unsnap the plastic assembly from the vents and remove the filter. 3. Wash and replace the filter, or if desired, install a new filter, and snap the filter retainer assembly back onto the vent assembly.

165. 9. Maintenance 9.3 Preventive Maintenance 9.3.3 Modular Industrial Workstations Perform a general visual inspection and exterior cleaning of each workstation as often as necessary to ensure proper operation of the equipment. Preventive maintenance procedures for the workstations should include the following: 1. Wipe down the exterior of the enclosure with a soft cloth. A damp cloth and/or a nonabrasive cleaner can be used for hard-to-remove spots. 2. Clean any dust buildup on disk drives (especially the signal connection areas), keyboards, control panels, and monitors. Use a soft cloth. 3. Check fans (if installed) for proper operation. 4. Check module status indicators for proper operation. Green light indicates normal operation. Red light indicates faulty operation.

166. 9. Maintenance 9.3 Preventive Maintenance 9.3.4 Monitor-Based Peripheral Devices As a rule, preventive maintenance on these devices should be limited to cleaning only and should be performed as often as necessary, or at least every twelve months. Wipe down the exterior of the device (excluding the monitor) with a soft cloth. A damp cloth and/or nonabrasive cleaner can be used for hard-to-remove spots. To clean the monitor, proceed as follows: 1. Select a screen that does not have direct access to the process, for example, the Initial display. 2. Remove power from the GCIO unit (annunciators are also deactivated). 3. Turn the monitor's power off. Do not move the mouse or depress any keys while the monitor is off. 4. Dampen - do not saturate - a clean, lint-free cloth with liquid glass cleaner. 5. Clean the screen by wiping with damp cloth, using circular wiping motion to avoid streaks. 6. Carefully dry the screen by wiping with a second clean, lint-free cloth. 7. Restore power to the monitor and GCIO.

167. 9. Maintenance 9.3 Preventive Maintenance 9.3.5 Printers All printers should be serviced every six months (or after 300 hours of operation), whichever occurs first. Refer to the associated printer user's guide (packed with the printer) and perform the following: 1. Perform a general visual inspection and cleaning of the printer. 2. Remove printer cover and inspect internal moving parts for signs of wear, broken or loose parts, frayed cables, and so on. 3. Take a clean, dry, soft cloth and dust the area around carriage shaft and platen. Remove any loose particles of paper and dust. 4. Lubricate printer as described in associated service instructions. 5. Restore printer power.

168. 9. Maintenance 9.3 Preventive Maintenance 9.3.6 Keyboard A keyboard should be cleaned at a frequency determined by the environment in which it is used. 1. Use a soft, lint-free cloth dampened with a mild detergent solution to clean the keys and large surfaces. 2. Clean confined areas between the keys with a vacuum cleaner equipped with a fine brush attachment.

169. 9. Maintenance 9.3 Preventive Maintenance 9.3.7 Mouse The following care and cleaning procedure applies to both the inner and outer area of the mouse: 1. The mouse is a very precise mechanical device, so handle it with care. Do not drop, hit, or otherwise subject it to shock. 2. Do not pull on the cable. It may cause damage to both the cable and connector. 3. Do not carry the mouse by holding onto the cable. 4. Be sure to place a clean sheet of paper or use a mouse pad between the mouse and the flat surface. Dirt and grit could collect on the ball. Try not to touch the ball on the bottom. 5. Do not use the mouse in extreme temperatures or in direct sunlight. 6. Do not allow the mouse to come in contact with liquid spills (water, solutions, and so forth). 7. The mouse housing should be cleaned with a lint-free cloth using a mild detergent. Use an unsoiled lint-free cloth to dry housing. 8. Do not disassemble the mouse. If the ball in the unit needs to be cleaned, remove it from the lower case by detaching the cover to the housing. Do not remove all the screws to remove the ball. 9. Use a lint-free cloth with mild detergent to clean the ball, and an unsoiled cloth to dry it.

170. 9. Maintenance 9.3 Preventive Maintenance 9.3.8 Data Storage Devices 1. Blow away any lint or dust accumulation on or near the face of the floppy disk and streaming tape drive casings. 2. Clean the outer plastic surface of the drive with a lint-free cloth or a sponge slightly dampened with water. Wipe off residue and dry with soft, lint-free cloth. Do not use abrasive cleaners, solvents, or strong detergents. 3. Blow away any lint or dust accumulation on the signal and power connectors at the rear of the drive. 4. For the streaming tape drive, clean the head using only Freon TF and polyurethane swabs, commonly available with VCR head cleaning kits. Wet the swab with the Freon TF solution, and wipe the head using an up and down motion. Use a dry swab to clean any remaining residue from the head.

171. 9. Maintenance 9.4 Fault Analysis Through the System Management facility, you can monitor the health of the system and perform diagnostic tests on all the system stations and associated peripheral devices. 9.4.1 Startup Diagnostics Startup diagnostics are invoked automatically as a result of a power-on reset, an error, or an off-line diagnostic command. The diagnostics exist in each station at all times and are of two basic types: Reportable diagnostic - Tests a station function which, if faulty, does not prevent the error from being reported over the network. Nonreportable diagnostic - Tests a station function which, if faulty, inhibits the station from communicating over the network.

172. 9. Maintenance 9.4 Fault Analysis 9.4.2 On-line Diagnostics On-line diagnostics consist of Carrier band LAN LI (LAN Interface) Cable Tests and Node bus Cable Tests. These tests are either operator-initiated or automatically invoked to isolate faults and to check the integrity of the communication path. 9.4.3 Off-line Diagnostics Off-line diagnostics are used to check for, or verify the proper "independent" operation of a station's internal components. These tests do not verify any external reason for failure, thus they can be individually bench tested without regard to the station's subsystem configuration.

173. 9. Maintenance 9.5 Corrective Maintenance 9.5.1 Module Status Indicators All power modules, Processor modules, LAN modules, and Fieldbus Modules have red and green status indicators that operate in accordance with the maintenance manual codes. 9.5.2 I/A Series Module Replacement The maintenance approach is oriented toward module replacement. Fault analysis provides assistance with isolating station and peripheral faults. The presence of status lamps ( LEDs ) on each module enables an initial detection of problems that can exist on the module level. In addition, any module can be replaced without affecting the operation of any other module, including the other module of a fault-tolerant pair. Replacement of modules is similar to installation, which is described in the System Equipment Installation.

174. 9. Maintenance 9.6 Discussion Exchange of ideas with trainees to talk about their own experiences and comments about maintenance related to the text in this chapter.

175. Power Distribution

176. 10. Power Distribution 10.1 Learning objectives Understand power distribution of control systems.

177. 10. Power Distribution 10.2 Power Connections Main power consists of primary and secondary power. Note the voltage and main power distribution requirements for each enclosure before you connect main power. The power should be connected through an uninterruptible power supply.

178. 10. Power Distribution 10.3 Connection Procedure To connect the power lines proceed as follows: 1. Switch off main system power. 2. Open the right side door of the enclosure to access the junction boxes. (Two junction boxes are located in the field termination area.) 3. Place the junction box power switches in the OFF position. 4. Remove the bottom cover from each junction box. 5. Route the power lines to the junction boxes. 6. Connect the power lines. 7. Replace the junction box covers. 8. Switch ON the main system power.

179. 10. Power Distribution 10.4 Earth Connections To make earth connections to the metal enclosures, locate one of the tapped holes along the bottom interior of the enclosure (see Figure). Use a ring type solderless crimp connector appropriate for the size of wire used, and use a star-type lock washer between the connector and the enclosure chassis.

180. 10. Power Distribution 10.5 Discussion Discuss power distribution schemes.

181. PLC Fundamentals

182. 11. Power Distribution 11.1 Learning objectives Know general PLC issues Understand the operation of a PLC Understand the different types of inputs and outputs.

183. 11. Power Distribution 11.2 Introduction Control engineering has evolved over time. In the past humans were the main methods for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logical control decisions. The development of low cost computer has brought the most recent revolution, the Programmable Logic Controller (PLC). The advent of the PLC began in the 1970s, and has become the most common choice for manufacturing controls. PLCs have been gaining popularity on the factory floor and will probably remain predominant for some time to come. Most of this is because of the advantages they offer. Cost effective for controlling complex systems. Flexible and can be reapplied to control other systems quickly and easily. Computational abilities allow more sophisticated control. Trouble shooting aids make programming easier and reduce downtime.

184. 11. Power Distribution 11.2 Introduction Control engineering has evolved over time. In the past humans were the main methods for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logical control decisions. The development of low cost computer has brought the most recent revolution, the Programmable Logic Controller (PLC). The advent of the PLC began in the 1970s, and has become the most common choice for manufacturing controls. PLCs have been gaining popularity on the factory floor and will probably remain predominant for some time to come. Most of this is because of the advantages they offer. Cost effective for controlling complex systems. Flexible and can be reapplied to control other systems quickly and easily. Computational abilities allow more sophisticated control. Trouble shooting aids make programming easier and reduce downtime. Reliable components make these likely to operate for years before failure.

185. 11. Power Distribution 11.3 Hardware Many PLC configurations are available, even from a single vendor. But, in each of these there are common components and concepts. The most essential components are: Power Supply - This can be built into the PLC or be an external unit. Common voltage levels required by the PLC (with and without the power supply) are 24Vdc, 120Vac, 220Vac. CPU (Central Processing Unit) - This is a computer where ladder logic is stored and processed. I/O (Input/Output) - A number of input/output terminals must be provided so that the PLC can monitor the process and initiate actions. Indicator lights - These indicate the status of the PLC including power on, program running, and a fault. These are essential when diagnosing problems.

186. 11. Power Distribution 11.3 Hardware The configuration of the PLC refers to the packaging of the components. Typical configurations are listed below from largest to smallest as shown in Figure. Rack - A rack is often large (up to 18” by 30” by 10”) and can hold multiple cards. When necessary, multiple racks can be connected together. These tend to be the highest cost, but also the most flexible and easy to maintain. Mini - These are similar in function to PLC racks, but about half the size. Shoebox - A compact, all-in-one unit (about the size of a shoebox) that has limited expansion capabilities. Lower cost, and compactness make these ideal for small applications. Micro - These units can be as small as a deck of cards. They tend to have fixed quantities of I/O and limited abilities, but costs will be the lowest. Software - A software based PLC requires a computer with an interface card, but allows the PLC to be connected to sensors and other PLCs across a network.

187. 11. Power Distribution 11.4 Inputs And Outputs Inputs to, and outputs from, a PLC are necessary to monitor and control a process. Both inputs and outputs can be categorized into two basic types: logical or continuous. Consider the example of a light bulb. If it can only be turned on or off, it is logical control. If the light can be dimmed to different levels, it is continuous. Continuous values seem more intuitive, but logical values are preferred because they allow more certainty, and simplify control. As a result most controls applications (and PLCs) use logical inputs and outputs for most applications. Hence, we will discuss logical I/O and leave continuous I/O for later.

188. 11. Power Distribution 11.4 Inputs And Outputs Outputs to actuators allow a PLC to cause something to happen in a process. A short list of popular actuators is given below in order of relative popularity. Solenoid Valves - logical outputs that can switch a hydraulic or pneumatic flow. Lights - logical outputs that can often be powered directly from PLC output boards. Motor Starters - motors often draw a large amount of current when started, so they require motor starters, which are basically large relays. Servo Motors - a continuous output from the PLC can command a variable speed or position.

189. 11. Power Distribution 11.4 Inputs And Outputs Outputs from PLCs are often relays, but they can also be solid state electronics such as transistors for DC outputs or Triacs for AC outputs. Continuous outputs require special output cards with digital to analog converters. Inputs come from sensors that translate physical phenomena into electrical signals. Typical examples of sensors are listed below in relative order of popularity. Proximity Switches - use inductance, capacitance or light to detect an object logically. Switches - mechanical mechanisms will open or close electrical contacts for a logical signal. Potentiometer - measures angular positions continuously, using resistance. LVDT (linear variable differential transformer) - measures linear displacement continuously using magnetic coupling.

190. 11. Power Distribution 11.4 Inputs And Outputs Inputs for a PLC come in a few basic varieties, the simplest are AC and DC inputs. Sourcing and sinking inputs are also popular. This output method dictates that a device does not supply any power. Instead, the device only switches current on or off, like a simple switch. Sinking - When active the output allows current to flow to a common ground. This is best selected when different voltages are supplied. Sourcing - When active, current flows from a supply, through the output device and to ground. This method is best used when all devices use a single supply voltage. This is also referred to as NPN (sinking) and PNP (sourcing). PNP is more popular.

191. 11. Power Distribution 11.5 Operation Sequence All PLCs have four basic stages of operations that are repeated many times per second. Initially when turned on the first time it will check its own hardware and software for faults. If there are no problems it will copy all the input and copy their values into memory, this is called the input scan. Using only the memory copy of the inputs the ladder logic program will be solved once, this is called the logic scan. While solving the ladder logic the output values are only changed in temporary memory. When the ladder scan is done the outputs will updated using the temporary values in memory, this is called the output scan. The PLC now restarts the process by starting a self check for faults. This process typically repeats 10 to 100 times per second as is shown in Figure.

192. 11. Power Distribution 11.5 Operation Sequence Self test - Checks to see if all cards error free, reset watch-dog timer, etc. (A watchdog timer will cause an error, and shut down the PLC if not reset within a short period of time - this would indicate that the ladder logic is not being scanned normally). Input scan - Reads input values from the chips in the input cards, and copies their values to memory. This makes the PLC operation faster, and avoids cases where an input changes from the start to the end of the program (e.g., an emergency stop). There are special PLC functions that read the inputs directly, and avoid the input tables. Logic solve/scan - Based on the input table in memory, the program is executed 1 step at a time, and outputs are updated. This is the focus of the later sections. Output scan - The output table is copied from memory to the output chips. These chips then drive the output devices.

193. 11. Power Distribution 11.5 Operation Sequence The input and output scans often confuse the beginner, but they are important. The input scan takes a snapshot of the inputs, and solves the logic. This prevents potential problems that might occur if an input that is used in multiple places in the ladder logic program changed while half ways through a ladder scan and thus changing the behaviors of half of the ladder logic program. This problem could have severe effects on complex programs. One side effect of the input scan is that if a change in input is too short in duration, it might fall between input scans and be missed. When the PLC is initially turned on the normal outputs will be turned off. This does not affect the values of the inputs.

194. 11. Power Distribution 11.5 Operation Sequence 11.5.1 The Input and Output Scans When the inputs to the PLC are scanned the physical input values are copied into memory. When the outputs to a PLC are scanned they are copied from memory to the physical outputs. When the ladder logic is scanned it uses the values in memory, not the actual input or output values. The primary reason for doing this is so that if a program uses an input value in multiple places, a change in the input value will not invalidate the logic. Also, if output bits were changed as each bit was changed, instead of all at once at the end of the scan the PLC would operate much slower

195. 11. Power Distribution 11.5 Operation Sequence 11.5.2 The Logic Scan Ladder logic programs are modeled after relay logic. In relay logic each element in the ladder will switch as quickly as possible. But in a program elements can only be examines one at a time in a fixed sequence. The ladder logic will be interpreted left-to-right, top-to-bottom. The ladder logic scan begins at the top rung. At the end of the rung it interprets the top output first, and then the output branched below it. On the second rung it solves branches, before moving along the ladder logic rung.

196. 11. Power Distribution 11.5 Operation Sequence 11.5.3 PLC Status The lack of keyboard and other input-output devices is very noticeable on a PLC. On the front of the PLC there are normally limited status lights. Common lights indicate; Power on - this will be on whenever the PLC has power. Program running - this will often indicate if a program is running, or if no program is running. Fault - this will indicate when the PLC has experienced a major hardware or software problem.

197. 11. Power Distribution 11.5 Operation Sequence 11.5.3 PLC Status The lack of keyboard and other input-output devices is very noticeable on a PLC. On the front of the PLC there are normally limited status lights. Common lights indicate; Power on - this will be on whenever the PLC has power. Program running - this will often indicate if a program is running, or if no program is running. Fault - this will indicate when the PLC has experienced a major hardware or software problem. These lights are normally used for debugging. Limited buttons will also be provided for PLC hardware. The most common will be a run/program switch that will be switched to program when maintenance is being conducted, and back to run when in production. This switch normally requires a key to keep unauthorized personnel from altering the PLC program or stopping execution. A PLC will almost never have an on-off switch or reset button on the front. This needs to be designed into the remainder of the system.

198. 11. Power Distribution 11.5 Operation Sequence 11.6 Role Play Conduct role plays for: 1. Introduce PLC and benefits. 2. Describe PLC hardware. 3. Introduce various inputs and outputs. 4. Describe PLC scan sequence.

199. Ladder Logic and SFC

200. 12. Ladder Logic and SFC 12.1 Learning objectives To be able to write simple ladder logic programs Understand basic functions for calculations and comparisons. Be able to develop SFCs, sequential flow charts, for a process.

201. 12. Ladder Logic and SFC 12.2 Ladder Logic Ladder logic is the main programming method used for PLCs . As mentioned before, ladder logic has been developed to mimic relay logic. Relays are used to let one power source close a switch for another (often high current) power source, while keeping them isolated. An example of a relay in a simple control application is shown in Figure. In this system the first relay on the left is used as normally closed, and will allow current to flow until a voltage is applied to the input A . The second relay is normally open and will not allow current to flow until a voltage is applied to the input B . If current is flowing through the first two relays then current will flow through the coil in the third relay, and close the switch for output C . This circuit would normally be drawn in the ladder logic form. This can be read logically as C will be on if A is off and B is on .

202. 12. Ladder Logic and SFC 12.2 Ladder Logic The example in Figure does not show the entire control system, but only the logic. When we consider a PLC there are inputs, outputs, and the logic. Figure shows a more complete representation of the PLC . Here there are two inputs from push buttons. We can imagine the inputs as activating 24V DC relay coils in the PLC . This in turn drives an output relay that switches 115V AC , which will turn on a light. Note, in actual PLCs inputs are never relays, but outputs are often relays. The ladder logic in the PLC is actually a computer program that the user can enter and change. Notice that both of the input push buttons are normally open, but the ladder logic inside the PLC has one normally open contact, and one normally closed contact. Do not think that the ladder logic in the PLC needs to match the inputs or outputs. Many beginners will get caught trying to make the ladder logic match the input types.

203. 12. Ladder Logic and SFC 12.2 Ladder Logic Many relays also have multiple outputs (throws) and this allows an output relay to also be an input simultaneously. The circuit shown in Figure is an example of this; it is called a seal in circuit or latch circuit. In this circuit the current can flow through either branch of the circuit, through the contacts labeled A or B. The input B will only be on when the output B is on. If B is off, and A is energized, then B will turn on. If B turns on then the input B will turn on and keep output B on even if input A goes off. After B is turned on the output B will not turn off.

204. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.1 Ladder Logic Inputs PLC inputs are easily represented in ladder logic. Below there are two types of inputs shown, normally open and normally closed inputs.

205. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.2 Ladder Logic Outputs In ladder logic there are multiple types of outputs, but these are not consistently available on all PLCs. Some of the outputs will be externally connected to devices outside the PLC, but it is also possible to use internal memory locations in the PLC. Five types of outputs are shown below. The first is a normal output, when energized the output will turn on, and energize an output. The circle with a diagonal line through is a normally on output, when energized the output will turn off. This type of output is not available on all PLC types. When initially energized the OSR (One Shot Relay) instruction will turn on for one scan, but then be off for all scans after, until it is turned off. The L (latch) and U (unlatch) instructions can be used to lock outputs on. When an L output is energized the output will turn on indefinitely, even when the output coil is de-energized. The output can only be turned off using a U output.

206. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.3 Programming The first PLCs were programmed with a technique that was based on relay logic wiring schematics. This eliminated the need to teach the electricians, technicians and engineers how to program a computer - but, this method has stuck and it is the most common technique for programming PLCs today. An example of ladder logic can be seen in Figure. To interpret this diagram, imagine that the power is on the vertical line on the left hand side, we call this the hot rail. On the right hand side is the neutral rail. In the figure there are two rungs, and on each rung there are combinations of inputs (two vertical lines) and outputs (circles). If the inputs are opened or closed in the right combination the power can flow from the hot rail, through the inputs, to power the outputs, and finally to the neutral rail. An input can come from a sensor, switch, or any other type of sensor. An output will be some device outside the PLC that is switched on or off, such as lights or motors. In the top rung the contacts are normally open and normally closed. This means if input A is on and input B is off, then power will flow through the output and activate it. Any other combination of input values will result in the output X being off.

207. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.3 Programming The second rung of Figure is more complex, there are actually multiple combinations of inputs that will result in the output Y turning on. On the left most part of the rung, power could flow through the top if C is off and D is on. Power could also (and simultaneously) flow through the bottom if both E and F are true. This would get power half way across the rung, and then if G or H is true the power will be delivered to output Y.

208. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.4 Move Functions The simple MOV will take a value from one location in memory and place it in another memory location. Examples of the basic MOV are given in Figure. When A is true the MOV function moves a floating point number from the source to the destination address.

209. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.5 Mathematical Functions Mathematical functions will retrieve one or more values, perform an operation and store the result in memory. Figure shows an ADD function that will retrieve values from N7:4 and F8:35, convert them both to the type of the destination address, add the floating point numbers, and store the result in F8:36. The function has two sources labelled source A and source B.

210. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.6 Block Operations A basic block function is shown in Figure 10.7. This COP (copy) function will copy an array of 10 values starting at N7:50 to N7:40. 12.2.7 Comparison of Values Comparison functions are shown in Figure. Previous function blocks were outputs, these replace input contacts. The example shows an EQU (equal) function that compares two floating point numbers. If the numbers are equal, the output bit B3:5/1 is true, otherwise it is false.

211. 12. Ladder Logic and SFC 12.2 Ladder Logic 12.2.8 Boolean Functions Figure shows Boolean algebra functions. The function shown will obtain data words from bit memory, perform an AND operation, and store the results in a new location in bit memory. These functions are all oriented to word level operations. The ability to perform Boolean operations allows logical operations on more than a single bit.

212. 12. Ladder Logic and SFC 12.4 Case Study Each Trainee should try to develop the following: 1. Ladder Logic for pump operation connected to the suction of a tank where two level switches are available for automatic operation and two push buttons are for start and stop. 2. SFC for loading three tanks through different valve. Tank 1 is load first, and then tanks 2 and three are loaded simultaneously. If the pressure switch on pump discharge line is alarming then tank 2 stops loading from pump and tank 1 would transfer to tank through different line. Tank 3 continues to load from pump.