CONTROL SYSTEMS TYPES 1 PLC 2 DCS 3

CONTROL SYSTEMS TYPES 1) PLC 2) DCS 3) PC- Based Controls. PLC • • • Sequentional logic solver PID Calculations. Advanced Subroutines BIT Operations. Data Transfer. Text Handling.

PLCDCS Selection Criteria • Cost of hardware, software, Integration Engineering, Design, Installation, Start-up and Commissioning, Validation documentation and Execution, Training, Spare parts, Maintenance, System service contract and system life cycle. • Reliability, Flexibility, Scalability and Validatability. • Ease of Database configuration, Graphics development, Interlocks and Batch processing. • Integration of High-level Application. • Control Philosophy for Centralized versus Remote Operator Console or both. • Compliance with an Industry batch standard such as ISA SP 88 and new Communication Protocol.

PROGRAMMABLE LOGIC CONTROLLERS PLC • • • Sequentional logic solver PID Calculations. Advanced Subroutines BIT Operations. Data Transfer. Text Handling. PLC Types • • Nano (less than 1 k RAM, 32 I/O) Micro Small Large (8 to 64 k RAM, 512 I/O More) Basic criteria for PLC Types • • • Memory Capacity I/O Range Packaging and Cost per Point

Applications : • • Machine controls. Packaging. Palletizing. Material handling and similar Sequential task. Advantages of PLC : • • They are fast and designed for the rugged industrial environment. They are attractive on Cost-Per-Point Basis. These Devices are less Proprietary ( E. g. . Using Open Bus Interface. ) These Systems are upgraded to add more Intelligence and Capabilities with dedicated PID and Ethernet Modules. Disadvantages of PLC : • • • PLC were Designed for Relay Logic Ladder and have Difficulty with some Smart Devices. To maximize PLC performance and Flexibility, a number of Optional Modules must be added This Product Family also create Training and Installation problems.

PLC Types • • Nano (less than 1 k RAM, 32 I/O) Micro Small Large (8 to 64 k RAM, 512 I/O More) Basic criteria for PLC Types • Memory Capacity • I/O Range • Packaging and Cost per Point

PLC Systems Installation in RCF 1. Siemens SIMATIC 115 U 110 U 2. Allen Bradley PLC 5/25 and 5/10 3. Allen Bradley SLC 5 4. GE Fanuc 90 - 30 Series 5. GE Fanuc 90 - 30 Series 6. Mitsubishi --- Ammonia I --- PGR, New Nitric Acid Plant --- KCL/DAP Bagging Plant, Ammonia I --- Ammonia Storage --- New Bagging Plant --- STP

PLC Cycle Programmable controller Inputs Outputs Machine or Process

PLC Signal Flow Input Module Processor Memory Output Modules Data Output Input Image Table I: 0/6 O: 0/7 I: 1/4 O: 1/5 Input Devices Output Devices Ladder Program I: 0/6 I: 1/4 O: 0/7 I: 1/4 O: 1/5 Programming Terminal O: 1/5

ALLEN BRADLEY PLC (DH+) PLC-5 Controller Workstation with RSLogix 5 Software Workstation Data Highway Plus Features : • Supports remote programming SLC-5/04 Controller • Common, existing standard • Peer-to-Peer communications

ALLEN BRADLEY PLC ARCHITECTURE (ETHERNET) Laptop Internet Modem PC Workstation PLC-5/20 E Controller. SLC-5/05 Controller. Ethernet PLC-5 Controller Ethernet Gateway. Data Highway Plus

Comparison chart --- ALLEN BRADLEY PLC

GE Fanuc - PLC • GE Fanuc PLC Architecture : Wireless Modem GE Fanuc ‘s series 90 -30 PLC Family. GE Fanuc 90/30 PLC 90 - 70 PLC’s Host Platform Remote Platform Wireless Modem GE Fanuc 90/30 PLC HMI Display PC

Siemens PLC Communication S 5 -115 H S 5 -155 H SINEC S 5 -135 U S 5 -155 U S 5 -100 U

Siemens PLC Architecture Program memory Internal program Memory (RAM) Memory submodule Timer Process Image For Inputs And Outputs Processor Counters Flags I/O Inputs Outputs I/O bus External Counters

Siemens Programming Methods The program is generally written down before it is loaded into the programmable controller. This can be done in the form of a • Statement list ( STL ) • Control system flowchart ( CSF) or • Ladder diagram ( LAD ). The subsequent loading of the program into the S 5 -100 U PC can take place in two ways : Online ( Direct to internal RAM ) or Off-line ( EEPROM or EPROM ), i. e. , with the programmer connected or not connected to the programmable controller.

Siemens S 5 -100 U Specification CPU 100 U Function range Boolean logic, bracketed operation, counter and timer functions, load, transfer, comparison and jump operation, arithmetic. Programming language STEP 5 Methods of representation STL, CSF, LAD. Execution time 70 msec. Program memory ( Internal RAM ) 1 K Flags 1024, ½ of which are retentive. Digital Inputs Digital Outputs 128 ( Max. ) Analog Inputs Analog Outputs 8 ( Max. )

Comparison chart --- SIEMENS - PLC MODEL TOTAL SYSTEM I/O SCAN RATE/1 K PROGRAM MEMORY SIZE DATA MEMORY SIZE 90 U 8 2 msec 4 KB 4 KB 95 U 8 2 msec 16 KB 100 U 8 70 msec 2 KB 102 U 16 7 msec 4 KB 103 U 32 1. 6 msec 20 KB 135 U 192 1. 1 msec 46 KB 64 KB 155 U 32578 0. 2 msec 640 KB or 1. 6 MB 640 KB or 1. 6 MB

PLC Architecture Evolution • Mid - 1970 s : Discrete Machine Control Programming Terminal Connection is Point to Point PLC Programming Language : I/O - Relay ladder logic - Flexibility in altering control system operation

PLC Architecture Evolution • Early - to - Mid 1980 : Discrete and Process Control MS - DOS Reasonable Computer Running PLC Programming Software PLC Programming Language : I/O - Ladder Program - PID - Data Storage

PLC Architecture Evolution • Late 1980’s to early 1990’s : Discrete and Process Control Windows PC running PLC Programming Software Connection in networked allowing Multiple PLC PLC became a part of the developing enterprise resource system I/O

PLC Architecture Evolution • Today : Enterprise Control Open Solutions NT - Based PC running Control Development Software Program Download Connection CE Based Open Control Unit Ethernet - enterprise network connection I/O

Ethernet was originally designed by Digital, Intel and Xerox (DIX) in the early 1970’s and has been designed as a broadcast system. The original format for Ethernet was developed in Xerox Palo Alto Research center (PARC), California in 1972. The two inventors were Robert Metcalf and David Boggs. Ethernet version 1. 0 and 2. 0 followed until the IEEE 802. 3 committee re-jigged the Ethernet II packet to form the Ethernet 802. 3 packet. Nowadays you will see either Ethernet II (DIX) format or Ethernet 802. 3 format being used. The ‘Ether’ part of Ethernet denotes that the system is not meant to be restricted only to one medium type, copper cables, fiber cables and even radio waves can be used. Briefly, stated Ethernet what is referred to as the Physical layer and the Data-link layers protocols. The physical layer defines the cable types, connectors and electrical characteristics. The Data link layer defines the format an Ethernet frames, the error checking method and the physical addressing method. As Ethernet is only a Physical/Data link layer other protocols need to be added on top of it to address the issues of routing, end-to-end data integrity and house specific network task are carried out.

Ethernet 10 Base 5 Traditionally, Ethernet is used over ‘thick’ coaxial cable called 10 Base 5 ( the 10 denotes 10 Mbps, base means that the signal is baseband i. e, takes the whole bandwidth of the cable, 5 denotes 500 m maximum length ). The minimum length between stations is 2. 5 m. The cable is run in one long length forming a ‘Bus Topology’. The segments are terminated by 50 ohm resistor and the shield should be grounded at one end only. 10 Base 2 Thin Ethernet (Thinnet) uses RG-58 cable and is called 10 Base 2 (the 2 denotes 200 mtr maximum length cable). Each station connects to the Thinnet by way of Network Interface Card (NIC). At each station the Thinnet terminates at a T-piece and at each end of the Thinnet run a 50 ohm terminator is required to absorb stray signals thereby preventing signal bounce.

Ethernet 10 Base. T Nowadays, it is becoming increasingly important to use Ethernet across Unshielded Twisted Pair (UTP) or Shielded Twisted Pair (STP), this being called 10 Base. T (the T denotes twisted pair). UTP is installed in star wire format and Ethernet Hubs with UTP ports (RJ 45) centrally located. Also there should be no more than a 11. 5 db signal loss and the minimum distance between devices is 2. 5 meters. The advantages of the UTP/STP technology are gained from the flexibility of the system, with respect to moves, changes, fault finding, reliability and security. 10 Base. F standard developed by IEEE 802. 3 committee defines the use of Fiber for Ethernet. 10 Base. FB allows upto 2 Km per segment and is defined for Backbone application such as cascading repeaters. 10 Base. FL describes the standards for the Fiber optic links between stations and repeaters allowing upto 2 Km per segment on multimode Fiber.

Ethernet The following table shows the RJ 45 pin outs for 10 Base. T : RJ 45 Pin Function Colour 1 Transmit White/Orange 2 Transmit Orange/White 3 Receive White/Green 4 Blue/White 5 White/Blue 6 Receive Green/White 7 White/Brown 8 Brown/White

Ethernet Topology Segmented (star) topology Workstation Bus topology Workstation Switched Hub Controller

PLC conceptual overview Process Graphics History & Trend Alarm & Events SCADA configuration editor Other Aspect system SCADA Control Aspect OP Client OPC server SCADA server Real-time database opc Modbus comli Protocol xx yy ABB Siemens Allen Bradley GE Fanuc ….

Process control Software characteristics The most important feature of process control system is that it needs to be reliable. The process control system used has to be completely crash-proof and any changes in the system need to be made on-line. The process control needs to be made real time, which means that it can update the I/O data table and process the control program in the time required by the process. A process control system that is deterministic refers to whether the operating system allows the highest priority task to work without interruption from task with lower priority. Software offerings in the automation and the process control fields must be versatile and open enough to address the needs of different applications. Finally the chosen solution must deliver tangible, quantifiable values such as : 1. Reducing project implementation time and cost. 2. Improving time-to-market. 3. Achieving higher production and quality. 4. Cutting maintenance and training cost. 5. Increasing profits.

PC-based control system features Unlike the other systems, PCs provide a more open architecture making them ideal for improving, optimizing and integrating the overall automation process, as well as conducting control task. In addition PCs offer the following features : • Lower cost. • Ease of use. • Graphical user interface. • Easy integration of logic, motion and process control. • Simplified application development. • Software portability • Independence from proprietary control system. Using PCs enable the following functions, • Millisecond time stamping which is essential to utilities. • Real time control. • Sequence of events. • Alarming. • Data collection.

Windows NT features Windows NT is gaining ground in open control because of the following advantages : • User acceptance. • Corporate interoperability • Ease of use. • Connectivity. • Scalability for small and large application. • • • However, Windows NT has the following disadvantages : Needs a lot memory and processing power. Optimized for office, not control, requirements. Requires a disk drive which may fail. Depends on single vendor. Reboots at unexpected times Unstable operating system.

QNX Features QNX real-time operating system, has evolved from the first-ever micro-kernel operating system for PCs into one of the best selling and most trusted operating systems for mission critical application. Today, QNX is the real time operating system in industrial automation, hand held devices, controllers and soft PLCs QNX is recognized as : • The fastest and most dependable real time operating system. • The most proven high speed, deterministic real time kernel. • Having a hard real time engine that gives PLC-style control. • Enabling data acquisition with milliseconds resolution. • Providing a fault-tolerant architecture on which you can run control, events, alarms in a virtually crash-proof environment.

PLC Programming Standards The open, manufacturer-independent programming standard for automation is IEC 61131 -3. You can thus choose what configuration interface you wish to use when writing your application : • • • Ladder Diagram Instruction List Function Block Diagram Sequential Function Chart Structured Text All users, be they plant electrician or computer scientists, thus have a configuration interface in which they can feel at home.

Industrial IT Trends The availability of information is becoming increasingly crucial in the view of growing global competition. In future, a decisive competitive edge can only be achieved by providing the right information at the right time, in the right place and in the right form for the right person. these leading- edge application are continuously optimized and repositioned. Industrial IT consists of five components: 1. 2. 3. 4. 5. Engineering IT Operation IT Production IT Optimization IT Evolution / Information

Industrial IT Trend Business Systems Sales & Marketing ION OPTIMIZAT TY Operation & Maintenance ASSET UCTIVI Plant & Process Eng. Real-time Automation & Information e-PROD Planning & Scheduling Distribution Plant