Automatic Control System VII. Controller

transmitter actuator Structure of control system Process the name of mathematical model of the plant Material flow sensorstransducer actuating unit actuating drive controller operator desk Visualisation software SCADA (Supervisory control and data acquisition) Simulation software Control software Standard signals Variables Standard industrial I/O interface

Process controller and typical application field Process controller ready to use for industrial control and it’s possible the hardware redundancy and integrate the functionality of control and SCADA software. Application field process industry applications (paper, primary metals, food processing, and so on.) batch-type control (chemicotechnology, pharmaceutic chemistry, or injection molding machines, and so on.) Programmability standard control languages IEC and SCADA depending of factory

PLC familyes Control relays 8-20 I/O, limited memory size, only LD programming languages with limited and not standard instructions. Compact PLC I/O, normal memory size, standard IL, LD, FBD programming languages with limited instructions. Modular PLC with compact unit flexible arrangement up to 800 I/O, different memory size, standard IL, LD, FBD programming languages. Modular PLC with rack system Higher I/O number, memory size, CPU frequency, network ability. All standard programming languages are used.

Structure of modular PLC Programming device CPU module Local extension I/O module Network station Remote extension I/O module

MCC Variable Speed Drives S800 I/O S900 I/O (Ex) Workplaces Control Network Remote Clients System Servers Fieldbus High Speed Linking Devices (FF HSE/H1, PB DP/PA) Process Automation Process Automation and Safety OperatorEngineeringMaintenance Safety Network arrangement

© ABB GroupSeptember 13, 2015 | Slide 8 CPU Terminal base (“TB 711F”) CPU (“PM 783F”) Local I/O Modules (Up to 8) I/O Terminal Units (up to 8) FBP (Field Bus Plug) * RS232/485 DIAG RS232/485 SER (MODBUS) Field Bus Coupler Connector * Ethernet (RJ-45) 24 VDC Power connector AC 700F kontroller V9.1

Industrial software Simulation software Facilities: Involving differential equations, matrix, etc. Converting between frequency and time domain. Charting functions. Creating block models. Control software Content of control task for industrial computer (process control), or intelligent devices in laboratory (scope, frequency generator, power supply, etc.) Visualisation software Instead of classic operator desk (push button, dial indicator)

Control software Control software needs a model of the process Define correct interface between process and controller. (using standard signals) Dividing into simpler part of the process. Choosing control strategies. Creating control task, and define the parameters.

Standard industrial I/O interface for signals Digital I/O galvanic isolation 24 VDC logic (0 -7 V DC, V DC ) Analogue I/O Usually no galvanic isolation Typically: 4-20 mA signal area Typically resolution: 12 bit

Dimensionless technique Controlled, measured variable feedback signal action signal manipulated variable A/D conversion control task D/A conversion max min 20 mA 4 mA max min 20 mA 4 mA Domain of variability

Program structure of PLC control program Deafault task Periodic task Event task System task Priority Program A1 Program An Program E1 Program En Program Rn Program R1 Program Pn Program P1 Function block 1 Function block N Function N Function x Function 1 Data FB1/1 Data FB1/2 Data FB1/3 The system programs handle the error, keep the connection with operator, and so on. Function block 2

Programs, function blocks, functions The programs can be written any standard languages. Different languages can be used in the project. The function blocks and the function are well tested subprograms. The function blocks have more input and more output variables, which can be catch from any programs. The functions have more input and one output variables. The output variables appear in the working register of CPU and needs handle.

How the programs use the CPU t t t t D P E S A1A2A3A1 P1 A2A3A1A P E1 P AAA3A1A2A3A1 R1 A3A1A2A3A

Cyclic processing of the user program not use loop instruction (for, until..) at the end the program the processing starts again automatically Write data interrupt Standby PLC selftest Process user program Read data

The standard control languages IEC Structural Text similar to QuickC Instruction Line similar to assembly Ladder Diagram graphical language similar to contact plan Function Block Diagram graphical language similar to digital circuit plan Function Chart graphical language and text languages by IEC848 standard

Structure of Instruction line LabelInstruction Symbolic name for variable Comment These are always required It is used like the target of the jump instructions. It relates to the variable. JumpsLabel Calls Symbolic name for function block or function

Structure of jump’s instructions A CB D yes label yes yes jump conditional A no label unconditional jump no jump unconditional B C D

Structure of Call’s instructions User program Function block Data_1 Data_2 call name The same type of function blocks or functions can be called more times with different name and so data block. The call’s instructions can be used in the function block program too. return

Instructions of IEC LD, LDN S, R ST, STN AND, ANDN OR, ORN XOR, XORN LT, LE, EQ, EN, GE, GT JMP, JMPC, JMPCN CAL, CALC, CALCN RET, RETC, RETCN all variables bool variables all variables bool variables all variables (the result is bool) label name of function block or function

Store, Set, Reset output instructions StoreST In all scan the output result depends on the actual value of the contacts. SetS In the first scan when the logical result of contacts actual value equals true the output register (variable) is set high, and remains in this state independent the contacts actual value until a reset instruction. ResetR In the first scan when the logical result of contacts actual value equals false the output register is reset

Variables of IEC BOOL BYTE, WORD, DWORD integer (INT), short integer (SINT), double integer (DINT), unsigned integer (UINT),... REAL TIME DATE TIME_OF_DAY DATE_AND_TIME STRING bool variables bit sequence variables digital variables real number T#0h0m0s0ms D# (YYYY-MM-DD) TOD#00:00:00 (HH:MM:SS) DT# :00:00

Structure of Instruction line program Sequence Smallest part of a instruction line program the sequence consisting of one or more instruction line. Syntactic of sequence –Started one load instruction (LD, LDN) and finished one or more result instruction (ST, STN, S, R, JMPC, JMPCN, CALC, CALCN). –Inside the sequence the type of the variables is the same. –JMP, CAL, RET are the one line instructions.

Bool algebra AND OR XOR The relaycoil1 is energised if the contact1 and the contact2 are closed. The relaycoil2 is energised if the contact1 or contact2 are the closed. The relaycoil3 is energised if either the contact1 or the contact2 are closed.

Sequence AND OR XOR LD contact1 AND contact2 ST relaycoil1 LDN contact1 OR contact2 ST relaycoil2 LD contact1 ANDN contact2 LDN contact1 AND contact2 OR ST relaycoil3 LD contact1 XOR contact2 ST relaycoil3 Circuit connections between ends Logical closed instruction series

Structure of Ladder diagram Type

Suggested flowchart of the PLC program If the result of the conditions is false the actions aren’t processed and begins automatically examination of the next conditions. The jumped actions aren’t processed. It remains the latest value. There aren’t conditions before JMP, CAL instructions Actions conditions Actions Jump’s label Call’s name

Steps of creating control program Flowchart of the program define input, output, and internal variables Hardware topology file Edit program file and reference file definition of variables, edit program, syntax check Compile editing program convert to machine code, error massages Transfer (download) to PLC Test and commissioning start/stop program running, display program in running Modify program