M-system SC100 Series Applications Manual
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M-system SC100 Series Applications Manual

Multi-function pid controller; function block
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SC100/200 Series
MULTI-FUNCTION PID CONTROLLER
FUNCTION BLOCK
APPLICATION MANUAL
1
SC100/200 Series Function Block Application Manual EM-6460-C

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  • Page 1 SC100/200 Series MULTI-FUNCTION PID CONTROLLER FUNCTION BLOCK APPLICATION MANUAL SC100/200 Series Function Block Application Manual EM-6460-C...

  • Page 2: Table Of Contents

    C ont ent s 1. INTRODUCTION ..................5 1.1 SC100/200 MULTI-FUNCTION PID CONTROLLER ...............5 1.2 PROGRAMMING LANGUAGE ....................6 1.3 CONNECTING BETWEEN FUNCTION BLOCKS ..............7 1.3.1 CONNECTING ANALOG SIGNALS ................7 1.3.2 CONNECTING DISCRETE SIGNALS ................8 1.4 CODING PRINCIPLE ......................9 2. COMMON FEATURES ................. 11 2.1 FUNCTION BLOCK PROCESSING ORDER ...............
  • Page 3 4.3 CONTROL LOOP CONFIGURATION EXAMPLES ..............21 4.3.1 CASCADE CONTROL ....................21 4.3.2 RATIO CONTROL ......................24 4.3.3 PROGRAM CONTROL ....................25 4.3.4 OVERRIDE CONTROL ....................28 4.3.5 PD/PID SWITCHING ....................30 4.3.6 BATCH PID CONTROL ....................33 4.3.7 NON-LINEAR PID CONTROL..................36 4.3.8 GAP CONTROL ......................38 4.3.9 PROPORTIONAL CONTROL ..................39 4.3.10 VARIABLE PID CONTROL ..................41 4.3.11 SAMPLING CONTROL ....................43 4.3.12 DEAD TIME COMPENSATION ..................45...
  • Page 4 6. SEQUENTIAL CONTROL BLOCK ............85 6.1 GENERAL DESCRIPTIONS ....................85 6.1.1 CONFIGURATION OF SEQUENTIAL CONTROL BLOCKS ........85 6.1.2 SEQUENTIAL CONTROL COMMANDS ..............86 6.2 RELAY SEQUENCE ......................90 6.2.1 GENERAL DESCRIPTIONS ..................90 6.2.2 LADDER COMMAND DESCRIPTIONS ...............91 6.2.3 FREQUENTLY USED CIRCUIT CONFIGURATIONS ..........93 6.3 STEP SEQUENCE .......................95 6.3.1 GENERAL DESCRIPTIONS ..................95 6.3.2 STEP COMMAND DESCRIPTIONS ................96...

  • Page 5: Introduction

    1. INTRODUCTION This manual explains basic programming and processing principles of the SC100/SC200 Series Multi-function PID Control- ler, and detailed functions of the software function blocks including their coding examples. These principles are also applicable to MsysNet remote I/O modules connected via peer-to-peer communication network, with differences in I/O specifications, i.e.

  • Page 6: Programming Language

    1.2 PROGRAMMING LANGUAGE Analog instruments for feedback control (PID controllers and function modules) and relay control circuits for sequential (logic) control functions are replaced with software function blocks connected between each other in the programming just like physical wiring. No specialized programming skill is required. The figure below shows an example describing combined analog and sequential control functions realized on the software programming.

  • Page 7: Connecting Between Function Blocks

    1.3 CONNECTING BETWEEN FUNCTION BLOCKS A function block is referred to with Group No. in which it is registered. Group + terminal numbers are referred when connect- ing a block to another. Discrete signals are handled in a different manner from analog signals. 1.3.1 CONNECTING ANALOG SIGNALS Group and terminal numbers of an analog signal source are registered at the destination function block where the signal is taken in and used.

  • Page 8: Connecting Discrete Signals

    1.3.2 CONNECTING DISCRETE SIGNALS Discrete signals are registered in sequential control blocks: An input is approximated to a relay, while an output is to a coil. Inputs and outputs are represented in logic sequence commands. One block can contain at the maximum of 89 commands. Multiple blocks can be connected in serial to handle more commands.

  • Page 9: Coding Principle

    1.4 CODING PRINCIPLE A temperature control loop with one PID control block is given as an example to explain how to proceed in coding. LOOP CONFIGURATION TIC (0-80°C) annunciator hot water tank steam control valve temperature (reverse action) sensor BLOCK DIAGRAM Sequence G04 : Field Terminal G05 : Field Terminal...
  • Page 10 GROUP [04] SCxxx Extension Field Terminal 1 ★: Setting data ITEM MDFY DATA INPUT DISPLAY (e.g.) CONTENTS MD: 12 EXTENSION FIELD TERMINAL 1 (model) ANALOG OUTPUT CONNECTION TERMINAL ★ 25 GGNN M1#: 0225 Mv 1 connection terminal (error if not connected) ▲...

  • Page 11: Common Features

    2. COMMON FEATURES 2.1 FUNCTION BLOCK PROCESSING ORDER Field inputs are read in every computation cycle (basic control cycle) and each function block operates in turn. After the last function block has been processed, the values set at the field terminal block are output. START •...

  • Page 12: Reading & Sending Data/Parameters

    2.2 READING & SENDING DATA/PARAMETERS Paths to read or send data and parameters are categorized in the following three types: Path (1) is a basic connecting method, while Paths (2) and (3) are used to apply a set of parameters at a specific point in the control sequence. GG Function Block output switch...

  • Page 13: Communication Terminals

    3. COMMUNICATION TERMINALS SC200/ 210 When built-in input and output signals available at Field Terminal blocks (Group 01, 04 and 05) are not enough, external input and output signals can be used by using Communication Terminal blocks. Those of remote I/Os and controllers connected via peer-to-peer communication network (NestBus) are available.

  • Page 14: Control Blocks

    4. CONTROL BLOCKS 4.1 CONTROL BLOCK TYPES Two control blocks of the following types are available, registered in Group 02 and 03. • Basic PID • Advanced PID • Manual Loader • Ratio Setter • Indicator 4.1.1 SIMPLE LOOP CONTROL PID control function is applied to Group 02 and 03 to realize two independent PID control loops. In the following example, Group 02 and Group 03 MV outputs are provided via respective MV output terminals of the Controller.

  • Page 15: Cascade Control

    4.1.3 CASCADE CONTROL PID control function is applied to Group 02 and 03, and the primary loop MV output is connected to the secondary loop SP input in the example shown. primary loop secondary loop SC100/200 Series Function Block Application Manual EM-6460-C...

  • Page 16: Pid Control

    4.2 PID CONTROL Refer to Basic PID and Advanced PID blocks in the SC100/SC200 Series Function Block List (EM-6460-B) for the following ITEM numbers and explanations. 4.2.1 PROCESS VALUE PV • Engineering unit range (ITEM 82 thr. 85) In order to set temperature range to 0.0-1200.0°C for example, set ITEM 82 (upper range) to ‘12000,’ ITEM 83 (lower range) to ‘0,’ ITEM 84 (decimal point position) to ‘1,’ and ITEM 85 (engineering unit) to ‘C.’ •...

  • Page 17: Alarm

    4.2.3 ALARM • Setpoint setting ITEM 19 PV high alarm setpoint (%) ITEM 20 PV low alarm setpoint (%) ITEM 21 Hysteresis (deadband) (%) common to high/low and deviation alarm ITEM 34 Deviation alarm setpoint (%) • Alarm trip status monitoring ITEM 22 PV high alarm status ITEM 23...

  • Page 18: Pid Control

    4.2.5 PID CONTROL PID control transfer function is expressed with the following formula: (1 − 1 / m) T G (s) = –––— × 1 + –––– + ––––––––––––— (1 + T s / m) where PB = Proportional band = Integral time = Derivative time m = Derivative gain (= 8)

  • Page 19: Output Compensation (Advanced Pid)

    • Auto-tracking bumpless transition The integral and derivative terms are adjusted automatically to avoid a bump in the control output signal when the control is switched from manual to automatic, or when a PID constant is changed. Adjustments are applied when: • A/M SW is turned from 0 (Manual) to 1 (Auto).

  • Page 20: Preset Value Sw

    4.2.8 PRESET VALUE SW • Preset value SW (Terminal 08, ITEM 52) The control output is fixed at a preset value when the switch is turned on. Use the terminal 08 to control it from a sequential control block. • Preset value (ITEM 53) Used to specify the preset value.

  • Page 21: Control Loop Configuration Examples

    4.3 CONTROL LOOP CONFIGURATION EXAMPLES 4.3.1 CASCADE CONTROL The main purpose for configuring a cascade control system is to eliminate, through use of a secondary controller, the influ- ence of disturbance on the primary loop, which enters through the secondary control loop. ■...
  • Page 22 ■ BLOCK DIAGRAM EXAMPLE (1): USING CONTACT DISTRIBUTOR BLOCK Using the external feedback (output tracking) function of the primary loop, the primary loop MV tracks current SP of the sec- ondary loop when the secondary is at Loc mode setting. This configuration realizes smooth control output transition of the primary loop with automatic tracking when the secondary loop control is switched to/from the Loc mode.
  • Page 23 ■ BLOCK DIAGRAM EXAMPLE (2): USING SEQUENTIAL CONTROL BLOCK The control output transitions smoothly with automatic tracking when the Cas/Loc control is switched, and the Auto/Man is switched at the secondary loop. external feedback Sequence temp ■ OPERATION FOR THE EXAMPLE (2) How to switch between A/M and C/L: • Always set the primary loop (TIC) to Auto mode.

  • Page 24: Ratio Control

    4.3.2 RATIO CONTROL Ratio control attempts to preserve a ratio relationship between two process variables. ■ LOOP CONFIGURATION EXAMPLE Ratio referenced ow tracking ow Secondary SP = Ratio x Primary PV ■ BLOCK DIAGRAM Ratio Sequence ■ OPERATION • Always set the primary loop (ratio setting) to Auto mode. • Constant setpoint control and ratio control is selected by the secondary loop C/L SW. ■...

  • Page 25: Program Control

    4.3.3 PROGRAM CONTROL Setpoint is provided as a preset ramp program running over time. ■ LOOP CONFIGURATION EXAMPLE Program Setter Complete steam temp ■ BLOCK DIAGRAM Ramp Program Setter Sequence preset value SW Complete temp SC100/200 Series Function Block Application Manual EM-6460-C...
  • Page 26 ■ OPERATION STEP 01 Control output: Preset output 0% Program Setter: Reset RESET Start command: SW turned ON STEP 02 Reset command: SW turned OFF Program Setter: Running RUNNING Final phase reached STEP 03 COMPLETE ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION...
  • Page 27 STEP 01 Program Reset • ‘Complete’ lamp OFF • Control output at preset value 0% STEP 01 • Program Run SW OFF STEP 02 Program Running • Control output at AUTO mode (preset SW OFF) STEP 02 • Program Run SW ON Final phase reached Final Phase STEP 03...

  • Page 28: Override Control

    4.3.4 OVERRIDE CONTROL Override control is used to take control of an output from one loop to allow a more important loop to manipulate the output, thus the output from two or more controllers are combined to manipulate a final control element. It is a typical application of external feedback (output tracking) function.
  • Page 29 ■ OPERATION Either the TIC or the FIC, the one that has a larger deviation from respective setpoints, overtakes control. When the A/M SW for the FIC loop is set to Manual, the TIC loop output takes in the external feedback (tracking output). FIC: External feedback CONTROL [TIC deviation >...

  • Page 30: Pd/Pid Switching

    4.3.5 PD/PID SWITCHING PD control is used while the control loop has a large deviation, and then the control is switched to PID once the deviation has become a small enough value. This method is used mainly to avoid ‘integral windup’ situation, an excess overshooting that occurs when the integral term accumulates a significant error during initial temperature rise in a batch control system (windup).
  • Page 31 ■ BLOCK DIAGRAM High/Low Alarm deviation external feedback Sequence output compensation Parameter Selector output compensation Parameter Setter reactor hot water tank Parameter Setter PD parameters (G02) PID parameters (G02) G02 : Control block (primary loop, reactor temperature) G03 : Control block (secondary loop, hot water tank temperature) G30 : High/Low Alarm (to detect deviation)
  • Page 32 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Primary loop control block Output compensation method set to ‘addition’ (for manual resetting) 3 1 2 1 Output compensation connection terminal (for manual resetting) 0 4 2 2 External feedback connection terminal (secondary loop PV) Secondary loop control block High/low alarm block 0 2 2 3...

  • Page 33: Batch Pid Control

    4.3.6 BATCH PID CONTROL The MV output is set to the maximum to quicken initial heating in a batch control process, and then reduced to an expected balanced output value before PID starts taking control. This is a typical control method employed for a batch control process with advantages of minimizing the initial heating time and avoiding an excess overshooting caused by accumulated integral term.
  • Page 34 ■ BLOCK DIAGRAM Parameter Selector Input Selector external feedback Sequence High/Low Alarm deviation reactor hot water tank G02 : Control block (primary loop) G03 : Control block (secondary loop) G30 : High/Low Alarm (to detect deviation) G31 : Input Selector G32 : Parameter Selector (output 1 and output 2) G81 : Sequential Control...
  • Page 35 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Primary loop control block 3 1 2 1 External feedback connection terminal (input selector output) Secondary loop control block High/low alarm block 0 2 2 3 X1 connection terminal (deviation output from the primary loop) s e t High setpoint (%) for deviation setpoint 1 s e t...

  • Page 36: Non-Linear Pid Control

    4.3.7 NON-LINEAR PID CONTROL Non-linear PID control is useful to deal with non-linearity problems typically found in pH process control. ■ LOOP CONFIGURATION EXAMPLE: NEUTRALIZATION CONTROL The titration curve around pH 7 with an extreme non-linearity is adjusted to provide a relatively constant gain over entire span by decreasing control gain around the equivalence point by multiplying it with a coefficient.
  • Page 37 ■ OPERATION Non-linear Gain, Deadband Function deviation – K1 : Gain (set to 1.000) K2 : Non-linear gain (0.000 ... 1.000) K3 : Gain (set to 1.000) A1 : Segment point (0.00 ... 100.00%) ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block...

  • Page 38: Gap Control

    4.3.8 GAP CONTROL Gap control is a variation of non-linear PID control strategy, with the non-linear gain set to ‘0.’ ■ LOOP CONFIGURATION EXAMPLE: STEAM PRESSURE CONTROL FOR A STEAM HAMMER Steam consumption signal in a steam hammer pulsates widely by piston movements. Attempting to control directly such pressure fluctuation could cause unwanted disturbance to the supply fuel flow.

  • Page 39: Proportional Control

    4.3.9 PROPORTIONAL CONTROL Proportional-only control without integral and derivative terms is widely used. The control method stabilizes the control loop without a risk of cycling as far as a certain deviation in control result is tolerated. ■ LOOP CONFIGURATION EXAMPLE: TANK LEVEL CONTROL in ow control valve (reverse action)
  • Page 40 ■ BLOCK DIAGRAM level ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block s e t Proportional band 0 . 0 0 Integral time (0.00 = no integral) 0 . 0 0 Derivative time (0.00 = no derivative) s e t Manual reset value SC100/200 Series Function Block Application Manual EM-6460-C...

  • Page 41: Variable Pid Control

    4.3.10 VARIABLE PID CONTROL Different sets of PID parameters are automatically applied following loop characteristics changes caused by switching sen- sor’s measuring range, control valves or set values (e.g. set values change in accordance with the progress of program steps as in 4.3.3 PROGRAM CONTROL).
  • Page 42 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block High/low alarm block 0 2 2 2 X1 connection terminal (control block current SP) s e t High setpoint A1 (%) for one zone division s e t Low setpoint A2 (%) for another zone division s e t Hysteresis (deadband) A3 (%) Parameter setter block...

  • Page 43: Sampling Control

    4.3.11 SAMPLING CONTROL Sampling control is used to deal with intermittent PV signals by using integral action and output hold function. It is typically applied to analyzers using gas chromatography or to processes with a large dead time. ■ LOOP CONFIGURATION EXAMPLE: END POINT CONTROL WITH A GAS CHROMATOGRAPH synchronization signal gas B...
  • Page 44 ■ OPERATION OUTPUT Output hold SW turned ON HOLD Timer t seconds completed Synchronization signal turned ON G30 Timer operating OUTPUT Output I action I ACTION Output hold SW turned OFF ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block Timer block Time setting (t Time unit (seconds)

  • Page 45: Dead Time Compensation

    4.3.12 DEAD TIME COMPENSATION Dead time compensation (Smith controller) is used when a large dead time exists and remains relatively stable in the pro- cess. ■ LOOP CONFIGURATION EXAMPLE: MOISTURE CONTROL AT THE ROTARY DRYER OUTLET Moisture sensor output changes slowly in a certain time period after the blower air supply volume is changed. rotary dryer blower moisture...
  • Page 46 ■ BLOCK DIAGRAM input compensation Addition G31 Addition function block is used to multiply the input compensation signal by Gain K. Dead Time Compensation moisture ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block Input compensation SW enabled Input compensation method set to ‘addition’ (Choose ‘subtraction’...

  • Page 47: On/Off Control

    4.3.13 ON/OFF CONTROL High/low alarm block is used to achieve ON/OFF control or interlocking. ■ LOOP CONFIGURATION EXAMPLES Example (1): Temperature control Example (2): Interlocking to prevent idle running of an agitator ON/OFF ON/OFF (open/close) steam temp level Example (3): Maintaining the minimum liquid level in a tank Water is supplied to maintain the minimum liquid level when it reaches the low limit after the feed has been stopped.
  • Page 48 ■ OPERATION FOR THE EXAMPLE (1) High/low alarm block has two trip points with a deadband used to prevent ON/OFF cycling around the setpoint. High Alarm Contact Operation Example high alarm contact A3 : deadband 100% input high alarm setpoint ON when the PV increases above the setpoint A1.

  • Page 49: Time-Proportioning On/Off Control

    4.3.14 TIME-PROPORTIONING ON/OFF CONTROL Output is turned on and off within a certain time interval in the ratio of MV signal. ■ LOOP CONFIGURATION EXAMPLE: TEMPERATURE CONTROL BY NICHROME WIRE HEATER ON/OFF temp proportional to the control output constant constant constant constant constant...
  • Page 50 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block Analog/pulse duration converter block 0 2 2 5 X1 connection terminal (control block MV output) Pulse cycle time CT (0...1000 seconds) Sequential control block 1 3 0 0 0 0 STEP 00 0 1 3 0 1 1 G30 - 11 Pulse duration contact output Y1...

  • Page 51: Loop Gain Compensation To Deal With Set Value Change

    4.3.15 LOOP GAIN COMPENSATION TO DEAL WITH SET VALUE CHANGE Loop gain varies depending upon process conditions and valve positions. Loop gain compensation attempts to maintain the gain to a constant level. ■ LOOP CONFIGURATION EXAMPLE: TEMPERATURE CONTROL LOOP IN CASCADE CONTROL Loop gain change could occur in the secondary loop of a proportional control function f (x)
  • Page 52 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block Output compensation SW enabled Output compensation method set to ‘substitution’ 7 2 2 1 Output compensation connection terminal (linearizer block output) Linearizer block 0 2 2 4 X1 connection terminal (control block PID output) s e t A1 Input 1 s e t...

  • Page 53: Loop Gain Compensation To Deal With Process Gain Change

    4.3.16 LOOP GAIN COMPENSATION TO DEAL WITH PROCESS GAIN CHANGE Loop gain varies depending upon process conditions and valve positions. Loop gain compensation attempts to maintain the gain to a constant level. ■ LOOP CONFIGURATION EXAMPLE: BLOWER OUTFLOW CONTROL Loop gain changes with the blower outflow due to its revolution speed change. The revolution speed signal is supplied to maintain the loop gain to a constant level.
  • Page 54 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Control block Input compensation SW enabled Input compensation method set to ‘substitution’ 3 0 2 1 Input compensation connection terminal (multiplication block output) Multiplication block 7 2 2 1 X1 connection terminal (linearizer block output) 0 2 2 3 X2 connection terminal (control block deviation output) 1 .

  • Page 55: Feedforward Control (Addition/Subtraction)

    4.3.17 FEEDFORWARD CONTROL (ADDITION/SUBTRACTION) Feedforward control attempts to measure disturbance to the control loop and to directly change MV output to prevent the appearance of any deviation beforehand. ■ LOOP CONFIGURATION EXAMPLE (1): BOILER PRESSURE CONTROL Upset in master steam flow is a major disturbance factor in the boiler pressure control (master control). The steam flow is measured and added to the PIC control output.
  • Page 56 ■ OPERATION FOR THE EXAMPLE (1) Feedforward signal (steam flow) is multiplied with an inexact differential coefficient and applied with an ‘addition’ type output compensation. · X · ––––––– · X 1 + T s where K = −K ■ CODING LIST ESSENTIALS FOR THE EXAMPLE (1) GROUP ITEM DATA...
  • Page 57 ■ LOOP CONFIGURATION EXAMPLE (2): BOILER DRUM LEVEL CONTROL (THREE-ELEMENT CONTROL)* The purpose of boiler feed water flow control is to maintain the drum level to a constant level. In order to achieve this goal, the drum level control loop (LIC) is cascaded into the feed water flow control loop (FIC). Violent fluctuations in the main steam flow causes a large disturbance to the drum level.
  • Page 58 ■ CODING LIST ESSENTIALS FOR THE EXAMPLE (2) GROUP ITEM DATA FUNCTION Control block Output compensation SW enabled Output compensation method set to ‘addition’ 3 1 2 1 Output compensation connection terminal (addition/subtraction block output) 0 3 2 2 External feedback connection terminal (secondary loop current SP) 0 , 1 Switching 0 / 1 by sequential control (‘1’...

  • Page 59: Feedforward Control (Multiplication/Division)

    4.3.18 FEEDFORWARD CONTROL (MULTIPLICATION/DIVISION) Feedforward control attempts to measure disturbance to the control loop and to directly change MV output to prevent the appearance of any deviation beforehand. ■ LOOP CONFIGURATION EXAMPLE: pH CONTROL Ratio control is used for the feed flow and the neutralizer flow through a metering pump. The ratio setting is changed by the PHC output.

  • Page 60: Computational Function Blocks

    5. COMPUTATIONAL FUNCTION BLOCKS 5.1 MATH FUNCTIONS Gain and bias calculation methods for normalization equation are somewhat complicated and prone to mistakes. The pur- pose of this section is to explain the procedures in their simplest form. 5.1.1 NORMALIZATION I/O signal ranges, gains and biases must be scaled to the normalized range of 0...1 when they are used in math function blocks.
  • Page 61 Gains and biases are calculated by the following equations based on the equation (3). – Y = –––––––––––– ....................Equation (4) – Y – Y = –––––––––––– ....................Equation (5) – Y – Y = –––––––––––– ....................Equation (6) – Y – Y = –––––––––––––––––––––––––––...

  • Page 62: Addition/Subtraction

    5.1.2 ADDITION/SUBTRACTION Three-input addition or subtraction function is available. For four or more inputs, combine multiple blocks. For two inputs, leave the connection terminal for unused input blank so that it is ignored. ■ EXAMPLE (1): ADDING THREE FLOW RATES Engineering unit function equation ......................(Equation 8) Engineering unit variables range...
  • Page 63 ■ EXAMPLE (2): AVERAGING THREE TEMPERATURE MEASUREMENTS Engineering unit function equation = (Y ) / 3 = 0.333Y + 0.333Y + 0.333Y ..........(Equation 10) Engineering unit variables range = 100 ... 500 °C = 0 ... 500 °C = 100 ... 600 °C = 200 ...
  • Page 64 ■ EXAMPLE (3): TEMPERATURE COMPENSATION FOR LIQUID DENSITY MEASUREMENT User’s process function equation γ = γ + α (t − t) = γ − α t + α t γ where : Compensated density (1.0 ... 1.3 kg/l) γ : Uncompensated density (1.0 ... 1.3 kg/l) α...

  • Page 65: Multiplication

    5.1.3 MULTIPLICATION Two-input multiplication function is available. For three or more inputs, combine multiple blocks. Normalization equation = (K ) (K ) + A ................Equation (1) where X : Variables (normalized to 0...1 range) : Gains (normalized to 0...1 range) : Bias (normalized to 0...1 range) Engineering unit function equation = (G...
  • Page 66 ■ EXAMPLE (1): RATIO CALCULATION IN A FLOW CONTROL PROCESS ow sensor Line 1 : Line 1 input, 0...1200 l/h : 0...4 (ratio) Ratio Calculation ratio setting (Multiplication Block) : Flow setpoint output, 0...2000 l/h Line 2 metering pump Engineering unit function equation ×...

  • Page 67: Division

    5.1.4 DIVISION Two-input division function is available. For three or more inputs, combine multiple blocks. Normalization equation = –––––––––– + A ....................Equation (1) where X : Variables (normalized to 0...1 range) : Gains (normalized to 0...1 range) : Bias (normalized to 0...1 range) Engineering unit function equation = ––––––––––...
  • Page 68 ■ EXAMPLE (1): FLOW RATIO CALCULATION Line 1 : Line 1 input, 0...40 m : Flow ratio output, 0...0.5 Ratio Calculation (Division Block) : Line 2 input, 0...60 m Line 2 Engineering unit function equation ÷ Y ......................Equation (8) The above equation is equivalent to the following one that matches the construction of the equation (2): = ––––––––...
  • Page 69 ■ EXAMPLE (2): TEMPERATURE RATIO CALCULATION Temperature ratio calculation is typically used for psychrometers. Engineering unit function equation + 10 = –––––––– ......................Equation (10) − 20 The above equation is equivalent to the following one that matches the construction of the equation (2): + 10 = –––––––––...

  • Page 70: Program Setting

    5.2 PROGRAM SETTING Two methods to create program patterns set over time are available: trapezoidal ramp program and line chart program. The trapezoidal ramp program is realized with Program Setter block, while the line chart program is realized with combined Lin- earizer and Accumulator blocks.
  • Page 71 ■ OPERATION STANDBY DI 1 turned OFF Start command: DI 1 turned ON PRG-1 PRG-2 nal phase reached PRG-1 to run: SW turned ON or DI 1 turned OFF PRG-1 output selected PRG-1 nal phase reached ON PRG-2 PRG-2 to run: SW turned ON PRG-2 output selected ■...

  • Page 72: Ramp Program With Extended Time Span

    5.2.3 RAMP PROGRAM WITH EXTENDED TIME SPAN Single batch program continuing for several tens of days can be realized by use of hold switches to halt and resume the program periodically. Parameters used in the program must be multiplied by appropriate conversion factors defined by the degree of time span expansion (clock pulse rate).
  • Page 73 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Counter block Count set to ‘9’ Program setter block Sequential control block 1 3 0 0 0 1 STEP 01 1 0 7 2 0 2 G72 - 02 PRG hold SW OFF 1 0 3 0 0 1 G30 - 01 Counter run SW OFF 0 2 8 0 0 5...

  • Page 74: Switching Among Multiple Ramp Programs

    5.2.4 SWITCHING AMONG MULTIPLE RAMP PROGRAMS The example below explains how to switch among multiple predefined ramp programs by using external switches. ■ BLOCK DIAGRAM EXAMPLE: THREE PROGRAMS Up to 8 programs can be switched using 8-point Input Selector Block with the following configurations. Ramp Program 1 PRG-1 Ramp Program 2...

  • Page 75: Line Chart Program

    5.2.5 LINE CHART PROGRAM Line chart program is realized by combining Accumulator and Linearizer blocks. Input axis of the linearizer’s line chart graph is applied with time, and its output axis is applied with set values. Time signal, provided from accumulated output at the ac- cumulator block, is determined with Parameter Selector block output multiplied by the counter rate in the accumulator block.
  • Page 76 ■ OPERATION Accumulator block: Reset STANDBY Run SW DI: turned ON Run SW DI: turned OFF Accumulator block: Running RUNNING Accumulator block preset value reached (99.9%) Contact output turned ON FINAL Accumulator block: Hold PHASE ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION...

  • Page 77: Accumulator

    5.3 ACCUMULATOR 5.3.1 GENERAL DESCRIPTION Accumulator block is used for continuous accumulation of analog input signals or for preset counter purpose. ■ OPERATION • Counter is automatically reset when the accumulated value reaches 10000 counts. • Fractions exceeding 10000 counts are added after the counter is reset. • When the counter reaches the preset value, the ‘preset value reached’ output Y1 is turned on. The Y1 is not reset automati- cally after the count has reached 10000, until the reset SW S1 is turned on. • Turn on the interrupt SW S2 in order to halt counting.

  • Page 78: Application Examples

    5.3.2 APPLICATION EXAMPLES ■ TYPICAL USAGE Accumulator Accumulator block is utilized with a counter rate setting. ■ ACCUMULATING MORE THAN 10000 COUNTS Combine Accumulator block with Counter block. Set the counter rate K so that the preset value of the accumulator is equiva- lent to the least significant digit of the counter.

  • Page 79: Driving An External Counter

    5.3.3 DRIVING AN EXTERNAL COUNTER Accumulated analog input signal is provided as pulse outputs to drive an external counter. ■ BLOCK DIAGRAM Accumulator High/Low Alarm Sequence Counter ■ OPERATION • Accumulator’s counter is automatically reset when the accumulated value reaches 10000 counts. • Fractions exceeding 10000 counts are added after the counter is reset. • One-shot output is provided to drive an external counter when the counter is reset by watching the Q0 (accumulated value output) with High/Low Alarm block. ■ CODING LIST ESSENTIALS GROUP ITEM DATA...

  • Page 80: Signal Memory

    5.4 SIGNAL MEMORY 5.4.1 GENERAL DESCRIPTION Analog signal is held temporarily by utilizing Analog Signal Hold block or Input Selector block. ■ ANALOG SIGNAL HOLD BLOCK Analog Signal Hold block (Model No. 83, abbreviation code AMM) is used to track Analog Signal Hold or hold input values according to a preset condition.

  • Page 81: Application Examples

    5.4.2 APPLICATION EXAMPLES ■ ZERO ADJUSTMENT Actual measured signal is captured and stored at the moment when ‘0’ is indicated on an external meter (INS: Input Selector). The stored signal is provided as offset to compensate newly measured signals (ADS: Addition/Subtraction). Input Selector hold command input...

  • Page 82: Batch Process Control

    5.5 BATCH PROCESS CONTROL 5.5.1 LOSS-IN-WEIGHT FEEDING The principle of loss-in-weight feeding is to control the feed of material out of a hopper or a tank by extracting a preset volume from a measured present volume (level or weight). ■ LOOP CONFIGURATION EXAMPLE The valve opens by Start signal and closes when deviation (extracted volume) alarm trips.
  • Page 83 ■ CODING LIST ESSENTIALS GROUP ITEM DATA FUNCTION Input selector block 0 4 2 3 X1 connection terminal (field terminal AI) 3 0 2 1 X2 connection terminal (output X0) Deviation alarm block 0 4 2 3 X1 connection terminal (present volume: field terminal AI) 3 0 2 1 X2 connection terminal (stored volume: input selector output X0) s e t...

  • Page 84: Flow Batch Control

    5.5.2 FLOW BATCH CONTROL ■ LOOP CONFIGURATION EXAMPLE: FIXED QUANTITY PREPARATION preparation batch start PBS valve batch reset PBS blowdown tank valve ■ BLOCK DIAGRAM Accumulator Sequence DI 1 DI 2 batch start batch reset preparation valve DI 1 and DI 2 are assigned to G30 Internal SW block as an example. ■...

  • Page 85: Sequential Control Block

    6. SEQUENTIAL CONTROL BLOCK 6.1 GENERAL DESCRIPTIONS A sequential control block uses switches and status signals from other blocks to condition and control various discrete sig- nals. All ON/OFF signals must be controlled via sequential control blocks. 16 types of commands are available for use in relay sequence or in step sequence descriptions. They are registered in 12 sequential control blocks.

  • Page 86: Sequential Control Commands

    6.1.2 SEQUENTIAL CONTROL COMMANDS GENERAL COMMAND FORMAT C C G G N N Example: 020101 Terminal No. Group No. Command Code CODE 01 : INPUT .................... Abbr. : IN The rst N.O. contact in a row. Condition is true when the contact X in the ladder diagram to the left is turned on or at ‘1,’...
  • Page 87 CODE 05 : OR....................Abbr.: OR A N.O. contact connected in parallel with the rst contact in a row. Condition is true when the contact X in the ladder diagram to the left is turned on or at ‘1,’ and the output ‘1’ is provided. Command : 0 5 G G N N X terminal No.
  • Page 88 CODE 09 : OUTPUT ON .................. Abbr. : ON A set coil in a latching relay circuit. The contact Y is turned on or at ‘1’ when the circuit is closed, and remains on when it is back open. OUTPUT OFF command (below) is used to turn it off. OUTPUT ON Y Command : 0 9 G G N N...
  • Page 89 CODE 12 : BRANCH..................Abbr. : BR Command to jump to a speci ed step of a speci ed group No. when the condition is true. Used also to connect between groups when more than one group is needed to describe a program. Command : 1 2 G G S S STEP No.

  • Page 90: Relay Sequence

    6.2 RELAY SEQUENCE 6.2.1 GENERAL DESCRIPTIONS Software relay circuits have the following differences from actual relay circuits. They must be carefully considered when you build software logic sequence programs, but on the other part this means new possibilities of configuring virtual circuits which are not possible by actual relays.

  • Page 91: Ladder Command Descriptions

    6.2.2 LADDER COMMAND DESCRIPTIONS AND (NOT) INPUT AND NOT AND NOT OUTPUT OR (NOT) INPUT OR NOT OR NOT OUTPUT MULTIPLE OUTPUTS INPUT OUTPUT OUTPUT OUTPUT NOT OUTPUT SHOT OUTPUT OUTPUT BRANCHING IN THE MIDDLE OF A ROW INPUT OUTPUT OUTPUT OR (NOT) + AND (NOT) INPUT...
  • Page 92 AND (NOT) + OR (NOT) Two circuits are connected via AND command without input. INPUT INPUT 0000 OUTPUT The following alternative command description with AND/OR in a reversed order is also valid. INPUT OUTPUT TWO AND (NOT) CIRCUITS WITH OR CONNECTION Two AND circuits are connected via OR command without input.

  • Page 93: Frequently Used Circuit Configurations

    6.2.3 FREQUENTLY USED CIRCUIT CONFIGURATIONS ONE-SHOT OUTPUT • One-shot output at an input rising • One-shot output at an input sinking INPUT INPUT NOT OUTPUT SHOT Y OUTPUT SHOT Y LATCHING CIRCUIT • N.O. reset input • N.C. reset input reset reset INPUT...
  • Page 94 FLIP-FLOP CIRCUIT • Y turns on/off once while X turns on/off twice. [ OPERATION ] INPUT • With contact X turned on, one-shot output y2 is provided to latch contact Y. OUTPUT SHOT y1 • With contact X turned off and on again, contact Y is on and INPUT NOT one-shot output y1 is provided to reset contact Y.

  • Page 95: Step Sequence

    6.3 STEP SEQUENCE 6.3.1 GENERAL DESCRIPTIONS In addition to relay (ladder) sequence type programming, the ‘step sequence’ type programming similar to sequential function chart is available. It is especially effective in describing a batch control process that needs exact conditioning to go to a next step in a batch. The following five (5) types of commands are available: OUTPUT ON : Once turned on, the output remains on until a next OFF command is received.

  • Page 96: Step Command Descriptions

    6.3.2 STEP COMMAND DESCRIPTIONS Advancing steps by the timing of computation cycles STEP 01 STEP 01 STEP 02 STEP 02 Moving to the next step when the step timer is completed STEP 01 STEP 01 TIMER 0 100 (setting at 100 seconds) Step timer completed? STEP 02 STEP 02...
  • Page 97 Moving to the next step when the condition is valid after the previous step has provided output STEP 01 STEP 01 OUTPUT Y1 ON OUTPUT Y1 ON CONDITION X1 INPUT X1 STEP 02 STEP 02 Moving to the next step after the previous step has provided output when the condition was valid STEP 01 STEP 01 INPUT X1...
  • Page 98 Overall sequence STEP 01 STEP 01 Step timer completed? TIMER 0 100 (setting at 100 seconds) Operating the output that needs to be always ON or OFF within the step OUTPUT Y1 ON OUTPUT Y1 ON Branch command (if necessary) CONDITION X1 INPUT X1 OUTPUT Y2 ON...

  • Page 99: Timer And Counter Blocks

    6.4 TIMER AND COUNTER BLOCKS Timer and Counter are similar in functions. Timer counts internal clock pulses while Counter counts external pulse signals. 6.4.1 TIMER Timer block has Count SW (S1), Interrupt SW (S2) and Complete status output (Y1) to control precise counting operation. • Counting is reset and off when S1 is off.

  • Page 100: Application Examples

    6.4.3 APPLICATION EXAMPLES PULSE COUNTER Run command Pulse input Complete status count complete INPUT Run command OUTPUT Count SW INPUT Pulse input OUTPUT Pulse input SW INPUT Complete status OUTPUT Complete SW ON DELAY TIMER Output is turned on in a certain time period after the run command is turned on. Run command Delay output count...
  • Page 101 TIME ACCUMULATOR Time counting is interrupted while the interrupt command X2 is on. Run command Interrupt command interrupt interrupt Output count count count complete INPUT Run command OUTPUT Timer run SW INPUT Interrupt command OUTPUT Timer interrupt SW INPUT Timer complete output OUTPUT Output CLOCK PULSE TIMER...
  • Page 102 DOUBLE TIMERS Two timers are used to count OFF and ON time respectively, to repeat ON and OFF in turn. Run command Run SW T1-S1 Run SW T2-S1 0.5 s 0.5 s INPUT Run command AND NOT T2-Y1 T2 complete output T2-Y1 T1-S1 OUTPUT...
  • Page 103 M-System, or from M-System’s authorized distributors or resel- Period, the purchaser must promptly (and, in any event not lers, for its own use not for resale, that the M-System products more than 30 days after the discovery of such failure) notify...

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