PLC for dummies BEICSFD Jernimo ORTOLA Marc QUILICHINI
PLC for dummies BE-ICS-FD Jerónimo ORTOLA Marc QUILICHINI icecontrols. support@cern. ch
PLC- Overview PLC n Programmable Logic Controller n n Designed for industrial processes. Works under severe conditions. Real time system. Handles sensors and actuators (I/O).
PLC- Functions n Process control n n Collects inputs (digital, analog) Runs the process control n n n Basic logic functions Complex algorithms (PID…) Safety functions Produces actions (outputs) Provides data to the supervision layer
PLC- Strength n n n Reliable. Used for safety systems. Robust. Resistant to electrical noise, vibration, impact, dust, heat. Extensive range of inputs/outputs. Extensive range of functionalities. Long term support by suppliers. Long service life, around 20 years.
PLC- Weak points n n Limited memory. Low performance. Dedicated programming environment. Different programming languages from different manufacturers.
PLC- Hardware Overview Supervisory Control And Data Acquisition SCADA ETHERNET TCP/IP PLC INDUSTRIAL FIELDBUS DIRECT WIRING REMOTE I/O SENSORS/ACTUATORS
PLC- Sensors / actuators n Device which converts the signal from one form to another. n Sensors n n n Analog: Temperature, pressure, humidity, level, flow, weight… Digital: Level, pushbutton (emergency stop), position switch, photoelectric sensor… Actuators n n Analog: valve, pump, heater, power supply… Digital: Signaling column, contactor, electro valve, switch, On. Off pump…
PLC- Hardware Overview Supervisory Control And Data Acquisition SCADA ETHERNET TCP/IP PLC INDUSTRIAL FIELDBUS DIRECT WIRING REMOTE I/O SENSORS/ACTUATORS
PLC- Periphery stations n Communication modules. n I/O Modules. n n Convert physical value into numeric value and vice versa. Function modules.
PLC- Communication modules n n n n Ethernet Profibus Profinet Modbus Ethernet IP CAN Serial, Point to Point AS-Interface
PLC- Input / Output modules n Analog n n 16 -bit signed from -32768 to 32767. Inputs: Resistance, Current, Voltage, thermocouple… Outputs: Current, voltage. Digital n n n 1 -bit Inputs: 120 v-230 v AC, 24 v DC Outputs: Relay, 120 v-230 v AC, 24 v-48 v-125 v DC.
PLC- Function modules n n n PID control Flow Camera controllers Numerical controllers Counters, positioners. Motor VFD or Soft Starter
PLC- Hardware Overview Supervisory Control And Data Acquisition SCADA ETHERNET TCP/IP PLC INDUSTRIAL FIELDBUS DIRECT WIRING REMOTE I/O SENSORS/ACTUATORS
PLC- Field. Bus. Overview n n n Industrial Network System Provides the PLC with I/Os Time deterministic
PLC- Field. Bus. Strength n n Controls multiple I/Os Saves cabling costs Allows distributed layouts and topologies Safety compliant
PLC- Field. Bus. Weak points n n n Sensitive to electromagnetic noise. Installation constraints (specific installation guidelines). Several different (incompatible) fieldbus standards.
PLC- Field. Bus. Standards n Profibus n n World. Fip n n Robust (radiation resistant) CANOpen. CANBus n n n Industry leader (56. 1 million nodes) Low cost, Easy to implement Used for ELMB at CERN Over Industrial Erthernet: n n Profinet (16. 4 million nodes) Ether. Net/IP Powerlink Ether. CAT
PLC- Field. Bus. Market share
PLC- Profibus. Technical data n Standard PROFIBUS EN 50 170 n Access Token ring. Master-Slave n Transmission rate 9. 6 kbit/s - 12 Mbit/s n Transmission technology electric: optic: wireless: n Nodes 127 maximun n Network lenght electric: optic: n Topology Daisy Chain, tree, star, ring, redundant ring n Used for Process communication, data transfer Shielded cooper pair twisted cable fiberoptics (cristal and plastic) infrared and radio 9. 6 km maximun 150 km maximun
PLC- Profibus Active nodes. Master PLC PC PROFIBUS Passive nodes. Slaves. PLC
PLC- Hardware Overview Supervisory Control And Data Acquisition SCADA ETHERNET TCP/IP PLC INDUSTRIAL FIELDBUS DIRECT WIRING REMOTE I/O SENSORS/ACTUATORS
PLC- Supported at CERN Siemens Schneider CERN-SIEMENS B 1130 A/GEN 31 -12 -1999 CERN-SCHNEIDER. B 1129/GEN 12 -11 -1999
PLC- Siemens n S 7 200 (low range) n n n Compact Low cost Small systems
PLC- Siemens n S 7 300 (medium range) n n n Modular Wide range of IOs Widely used Limited memory Limited range of fieldbuses
PLC- Siemens n S 7 400 (high range) n n n Redundant architecture Large memory High performance
PLC- Siemens – New CPUs n S 7 1500 (medium/high range) n n Modular Wide range of IO Large memory High performance
PLC- Schneider Small range (M 340) n n 4 Mb of memory 1024 digital I/O 256 analog I/O n n Medium range (PREMIUM) 7 Mb of memory 2040 Digital I/O max 512 Analog I/O n n High range (QUANTUM) 8 Mb of memory 8 000 Digital I/O 2500 Analog I/O
PLC- Schneider – New CPU n n High range (M 580) Compact High performance Modular
PLC- Processor Executes user program Writes Outputs Scan cycle 5 -500 ms Reads Inputs OS functions Comm Diagnostics
PLC- Memory access, IO access Internal 16 bits Data area 0 120 137 138 %MW 120 word %MF 137 Real IO devices are mapped in a memory. Input word %IW 0. 2. 3 Access to The Module Channel in The Module Input Boolean %I 0. 6. 3. 1 Bit in the Channel Output %QW 0. 2. 3 word Output %Q 0. 7. 3. 6 Boolean %QW 0. 2. 3 : = 16#0 F 00; %Q 0. 7. 3. 6 : = TRUE; N %MW 100 : = 12;
PLC- Programming languages n Languages defined in IEC 61131 -3 n Textual languages n n n Graphical Languages n n n Instruction List (IL) Structure Text (ST) Ladder (LD) Functional Bloc Diagram (FBD) Sequence (Stepper) n Sequential Function Chart (SFC) 31
PLC- Programming languages - IL n n n IL: Instruction List Fastest possible logic execution. Low level language
PLC- Programming languages - ST n n ST: Structured Text High level language Equations, table manipulation Complex statements and nested instructions n n n Iteration loops (REPEAT-UNTIL; WHILE-DO) Conditional execution (IF-THEN-ELSE; CASE) Functions (SQRT(), SIN())
PLC- Programming languages - LD n Traditional ladder logic is an easy-to-use graphical programming language that implements relay-equivalent symbol. n Intuitive. n Limited functionalities.
PLC- Programming languages - FBD n n FBD : Function Block Diagram Easy way of programming (intuitive) Easy way of debugging Limited for complex algorithms
PLC- Programming languages - SFC n n SFC : Sequential Function Chart A graphical method of representing a sequential control system (stepper).
PLC- Programming software tools n Siemens : Simatic Step 7 n n n Modular Wide range of functionalities Diagnostic tools Network configuration Schneider : UNITY Pro V 11. 0 n n Easy to manage Visualization facilities
PLC- Hardware Overview Supervisory Control And Data Acquisition SCADA ETHERNET TCP/IP PLC INDUSTRIAL FIELDBUS DIRECT WIRING REMOTE I/O SENSORS/ACTUATORS
PLC- SCADA communication n n n Ethernet TCP IP. Big amount of data transfer. Non deterministic. Big data transfer rates. S 7 Driver on TCP IP. Siemens. Modbus Driver on TCP IP. Schneider. OPC.
- Slides: 39