PLC Presentation new

Slide 1: 

PROGRAMMABLE LOGIC CONTROLLER

Control Systems Types: 

Control Systems Types Programmable Logic Controllers Distributed Control System PC- Based Controls

Programmable Logic Controllers : 

Programmable Logic Controllers PLC Sequential logic solver. PID Calculations. Advanced Subroutines. BIT Operations. Data Transfer. Text Handling.

Programmable Logic Controllers : 

Programmable Logic Controllers Applications : Machine controls, Packaging, Palletizing, Material handling, similar Sequential task as well as Process control. 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.

Programmable Logic Controllers : 

Programmable Logic Controllers PLC Types Nano (Small) Micro (Medium) Large Basic criteria for PLC Types Memory Capacity I/O Range Packaging and Cost per Point

Programmable Logic Controllers : 

Programmable Logic Controllers Components Central Processing Unit (CPU) Input Output Modules Power Supply Bus system

Programmable Logic Controllers : 

Programmable Logic Controllers Central Processing Unit It is a micro-controller based circuitary. The CPU consists of following blocks: Arithmatic Logic Unit (ALU), Program memory, Process image memory (Internal memory of CPU), Internal timers and Counters Flags CPU performs the task necessary to fulfill the PLC funtions. These tasks include Scanning, I/O bus traffic control, Program execution, Peripheral and External device communication, special functions or data handling execution and self diagnistics.

Programmable Logic Controllers : 

Programmable Logic Controllers Input module These modules act as interface between real-time status of process variable and the CPU. Analog input module : Typical input to these modules is 4-20 mA, 0-10 V Ex : Pressure, Flow, Level Tx, RTD (Ohm), Thermocouple (mV) . Digital input module : Typical input to these modules is 24 V DC, 115 V AC, 230 V AC Ex. : Switches, Pushbuttons, Relays, Pump Valve ON-OFF status.

Programmable Logic Controllers : 

Programmable Logic Controllers Output module These modules act as link between the CPU and the O/P devices in the field. Analog output module : Typical output from these modules is 4-20 mA, 0-10 V. Ex : Control Valve, Speed, Vibration. Digital output module : Typical output from these modules is 24 V DC, 115 V AC, 230 V AC. Ex. : Solenoid Valves, lamps, Actuators, dampers, Pump Valve ON-OFF control.

Programmable Logic Controllers : 

Programmable Logic Controllers Power Supply The power supply gives the voltage required for electronics module (I/O Logic signals, CPU, memory unit and peripheral devices) of the PLC from the line supply. The power supply provides isolation necessary to protect the solid state devices from most high voltage line spikes. As I/O is expanded, some PLC may require additional power supplies in order to maintain proper power levels.

Programmable Logic Controllers : 

Programmable Logic Controllers Bus System It is path for the transmission of the signal . Bus system is responsible for the signal exchange between processor and I/O modules. The Bus system comprise of several single line i.e. Wires / Tracks.

PLC Cycle: 

PLC Cycle Sense the Input Process the Logic Give Output Outputs Machine or Process Programmable controller Inputs

PLC Signal Flow: 

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

PLC Architecture Evolution: 

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

Slide 15: 

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

Slide 16: 

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

Slide 17: 

Today : Distributed I/O Modules Distributed I/O modules PLC Distributed I/O scanner Data Communication Bus PLC Architecture Evolution

Slide 18: 

Remote I/O Network SPLITTERS FIBER OPTIC LINK TAPS Remote I/O Today : Hot Redundant System PLC Architecture Evolution

Slide 19: 

Controller Controller Controller Controller Workstation Workstation Workstation Workstation Switched Hub PLC Architecture Evolution Today : Ethernet Technology in PLCs

Slide 20: 

Remote Platform Wireless Modem Wireless Modem PLC H M I Display PC PLC Architecture Evolution Today : Wireless communication PLC

PLC Systems of various vendors : 

PLC Systems of various vendors Siemens S5 -110U, 115U, 135U S7 - 200, 300, 400 Allen Bradley Micrologix 1000, 1200, 1500 SLC 5/01, 5/02, 5/03 PLC 5/10, 5/25 and 5/40 Modicon Nano Micro Premium Quantum

Configuration of PLC : Modicon: 

8 Analog Inputs 1 Analog Output Up/Down Fast Counter Up Counter Programming Terminal PC Connection Unitelway Port for connection of up to 5 Slaves PCMCIA memory expansion port PCMCIA communications port TSX37-22 Built in display for I/O (in-rack, AS-i) and Diag I/O Modules Configuration of PLC : Modicon

Configuration of PLC : Siemens: 

Configuration of PLC : Siemens CPU External Power Supply I/O Modules

Configuration of PLC : Allen Bradley: 

Configuration of PLC : Allen Bradley CPU Power Supply I/O Modules

Configuration of PLC : GE FANUC : 

Configuration of PLC : GE FANUC CPU I/O Modules Back plane

PLC Programming Standards: 

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

PLC DCS Selection Criteria: 

PLC DCS 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 Validitability. 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 SP88 and new Communication Protocol.