LG Industrial Systems GLOFA GM6 Series User manual

User’s Manual
LG Programmable Logic Controller
GLOFA GM6 Series
LG Industrial Systems

◎CONTENTS ◎

Chapter 1. GENERAL
1.1 Guide to User’s Manual················································································································1-1
1.2 Features········································································································································1-2
1.3 Terminology···································································································································1-3
Chapter 2. SYSTEM CONFIGURATION
2.1 Overall Configuration····················································································································2-1
2.2 Product List···································································································································2-2
2.2.1 GM6 series Configuration····································································································2-2
2.3 System ConfigurationTypes·········································································································2-3
2.3.1 Basic System·······················································································································2-3
2.3.2 Computer Link System········································································································2-3
2.3.3NetworkSystem··················································································································2-4
Chapter 3. GENERAL SPECIFICATION
3.1 General Specifications ················································································································3-1
Chapter 4. CPU MODULE
4.1 Performance Specifications ··········································································································4-1
4.2 Operation processing····················································································································4-2
4.2.1 Operation processing Methods ···························································································4-2
4.2.2 Operation processing at momentary power failure occurrence··········································4-3
4.2.3 Scan Time····························································································································4-4
4.2.4 Scan Watchdog Timer·········································································································4-4
4.2.5 Timer processing·················································································································4-5
4.2.6 Counter processing·············································································································4-7
4.3 Program········································································································································4-9
4.3.1 Program Configuration········································································································4-9
4.3.2 Program Execution Procedures ·························································································4-10
4.3.3 Task ····································································································································4-13
4.3.4 Error Handling ····················································································································4-19
4.3.5 Precautions when using special modules ··········································································4-20
4.4 Operation Modes ·························································································································4-24
4.4.1 RUN mode··························································································································4-24
4.4.2 STOP mode························································································································4-25

4.4.3 PAUSE mode······················································································································4-25
4.4.4 DEBUG mode·····················································································································4-25
4.4.5 Operation Mode Change····································································································4-26
4.5 Functions ·····································································································································4-28
4.5.1 Restart mode······················································································································4-28
4.5.2 Self-diagnosis·····················································································································4-30
4.5.3 Remote function·················································································································4-31
4.5.4 I/O Force On/Off function···································································································4-32
4.5.5 Direct I/O Operation function······························································································4-33
4.5.6 External Device Error Diagnosis function··········································································4-33
4.6 Memory Configuration·················································································································4-36
4.7 I/O No. Allocation Method············································································································4-38
4.8 Names of Parts····························································································································4-39
Chapter 5. BATTERY
5.1 Specifications································································································································5-1
5.2 Handling Instructions ····················································································································5-1
5.3 Battery Replacement····················································································································5-1
Chapter. 6 USING THE USER PROGRAM IN FLASH MEMORY
6.1 Structure ·······································································································································6-1
6.3Handling ······································································································································6-1
Chapter. 7 DIGITAL INPUT AND OUTPUT MODULES
7.1 Notes on Selecting Input and Output Modules·············································································7-1
7.2 Digital Input Module Specifications·······························································································7-2
7.2.1 16-point 24VDC input module (source/sink type) ·······························································7-2
7.2.2 16-point 24VDC input module (source type)·······································································7-3
7.2.3 32-point 24VDC input module (source/sink type)·······························································7-4
7.2.4 32-point 24VDC input module (source type)·······································································7-5
7.2.5 8-point 110VAC input module ····························································································7-6
7.2.6 8-point 220VAC input module······························································································7-7
7.3 Digital Output Module Specifications····························································································7-8
7.3.1 16-point relay output module·······························································································7-8
7.3.2 16-point transistor output module (sink type)······································································7-9

7.3.3 32-point transistor output module (sink type)·····································································7-10
7.3.4 8-point triac output module·································································································7-11
Chapter 8. POWER SUPPLY MODULE
8.1 Selection of power supply module································································································8-1
8.2 Specifications································································································································8-2
8.3 Names of Parts·····························································································································8-3
Chapter 9. BASE BOARD
9.1 Specifications································································································································9-1
9.2 Names of Parts·····························································································································9-1
Chapter 10. INSTALLATION AND WIRING
10.1 Installation··································································································································10 -1
10.1.1 Installation Environment···································································································10 -1
10.1.2 Handling Instructions········································································································10 -4
10.1.3 Module Loading and Unloading·······················································································10 -7
10.2 Wiring·········································································································································10 -9
10.2.1 Power Supply Wiring········································································································10 -9
10.2.2 Input and Output Devices Wiring ···················································································10 -11
10.2.3 Grounding·······················································································································10-11
10.2.4 Cable Specification for wiring·························································································10 -12
Chapter 11. MAINTENANCE
11.1 Maintenance and Inspection·······································································································11-1
11.2 Daily Inspection···························································································································11-1
11.3 Periodic Inspection······················································································································11-2
Chapter 12. TROUBLESHOOTING
12.1 Basic Procedures of Troubleshooting ······················································································12-1
12.2 Troubleshooting··························································································································12-1
12.2.1 Troubleshooting flowchart used when the POWER LED turns OFF ······························12-2
12.2.2 Troubleshooting flowchart used when the STOP LED is flickering··································12-3
12.2.3 Troubleshooting flowchart used when the RUN and STOP LEDs turns off ···················12-4

12.2.4 Troubleshooting flowchart used when the output load of the
output module does not turns on······················································································12 -5
12.2.5 Troubleshooting flowchart used when a program
cannot be written to the CPU module···············································································12 -6
12.3 Troubleshooting Questionnaire·································································································12 -7
12.4 Troubles hooting Examples ········································································································12 -8
12.4.1 Input circuit troubles and corrective actions·····································································12 -8
12.4.2 Output circuit troubles and corrective actions··································································12 -9
12.5 Error Code List·························································································································12 -11
Chapter 13. Dedicated Cnet communication for GM6
13.1 Introduction ·································································································································13-1
13.2 The example of system configuration·························································································13-2
13.3 The pin assignment of RS -232C connector of the GM6 dedicated Cnet communication ·········13-3
13.4 Frame structure ··························································································································13-4
13.5 List of commands························································································································13-7
13.6 Data type·····································································································································13-8
13.7 Execution of commands (Ex.)·····································································································13-9
13.8 Error code during NAK occurrence (for GM6 dedicated communication)································13-29
APPENDICES
Appendix 1. System Definitions ··································································································APP1 -1
Appendix 2. Flag List··················································································································APP2 -1
Appendix 3. Function/Function Block List··················································································APP3 -1
Appendix 4. Dimensions ·········································································································APP4 -1

Chapter 1. INTRODUCION
1 -1
Chapter 1. GENERAL
1.1GuidetoUser’sManual
This User’s Manual gives the specifications, performance and handling instructions for each of the necessary
units of the GLOFA-GM6 series PLC system.
The configuration of the User’s Manual is as follows.
No Title Content
Chapter 1 General Describes configuration of this manual, units’features and terminology.
Chapter 2 System Configuration Describes available units and system configurations in the GLOFA -
GM6series.
Chapter 3 General Specifications Describes general specifications of units used in the GLOFA-GM6
series.
Chapter 4 CPUModule Describes the performance, specifications and functions of the CPU
module.
Chapter 5 Battery
Chapter 6 Using the user program
inflashmemory
Chapter 7 Digital Input and output
Module
Chapter 8 Power Supply Module
Chapter 9 BaseBoard
Describes the specifications and handling instructions for other
modules except for the CPU module.
Chapter 10 Installation and Wiring Describes installation, wiring and handling instructions for reliability of
the PLC system.
Chapter 11 Maintenance Describes the check items and method for long term normal operation
ofthePLCsystem.
Chapter 12 Troubleshooting Describes various operation errors and corrective actions.
Chapter13
~
Chapter 16
Built-inspecial functions
of GM6 CPU module
Describes Cnet communication dedicated for GM6 CPU (Ch.13), RS -
422 master communication (Ch.14), PID control (Ch.15), and High
speed counter (Ch.16).
Appendix1 System Definitions Describes parameter setting for basic I/O module and communications
module.
Appendix2 Function/
Function Block List Describes the types and processing time of function/function block.
Appendix3 Flag List Describes the types and content of various flags.
Appendix4 Dimensions Shows dimensions of the CPU, I/O module and base board.
REMARK
1) This manual does not describes the special/communications module and programming for them.
For their own functions, refer to the related User’s Manual.

Chapter 1. INTRODUCION
1 -2
1.2 Features
1)GLOFA-GM series features:
(1) Design on the basis of international standard specifications(IEC 1131-3)
•Easy programming device support.
•Languages in compliance with IEC1131-3 are given. (IL/ LD / SFC)
(2) Open network by use of communications protocol in compliance with international standard specifications.
(3) High speed processing with an operation-dedicatedprocessorincluded.
(4) Various special modules that enlarge the range of application of the PLC.
2)GM6-CPUA/B/Cfeatures:
(1) Highspeedoperationprocessing
High speed processing of 0.5㎲/step with an operation-dedicatedprocessorincluded.
(2) Heightened Self-diagnosis
Cause of errors is easily found as error codes has been more divided in accordance with their contents.
(3) Restart mode setting
The Usercanset Cold / Warm restart mode in accordance with the environment.
(4) Debug operation
On-line debugging is available if the PLC operation mode is set to debug operation mode.
Debugging functions :
•Executed by one instruction.
•Executed by the break-point settings
•Executed by the device status
•Executed by the specified scan times
(5) Various Program Executions
Time driven task, external and internal contact task programs as well as scan program can be executed by
setting the execution condition. The user can set variously the program execution mode.
(6) Various data type

Chapter 1. INTRODUCION
1 -3
1.3 Terminology
The following table gives definition of terms used in this manual.
Terms Definition Remarks
Module A standard element that has a specified function which configures
the system. Devices such as I/O board, which inserted onto the
motherboardorbaseunit.
Example)
CPUmodule
Power Supply module
I/O module
PLC system A system which consists of the PLC and peripheral devices. A user
program can control the system.
Cold Restart
To restart the PLC system and user programs after all of the
data(Variables and programs of I/O image area, of internal register,
of timer of counter) were set to the specified conditions
automatically or manually.
Warm Restart
In the warm restart mode, The power supply Off occurrence will be
informed to the user program and the PLC system restarts with the
previous user-defined data and user program after the power
supply Off.
I/O Image Area Internal memory area of the CPU module which used to hold I/O
statuses.
Watch Dog Timer Supervisors the pre-set execution times of programs and warns if a
program is not completed within the pre-set time.
Function Operation Unit which outputs immediately its operation result of an input, while four arithmetic operations comparison operation store
their results in the inside of instructions.
Function Block Operation Units which store operation result in the inside of instruction such as timer and counter and use the operation results
which have been stored through many scans.
Symbolic
Variable
Variables used after the user’s definition of their names and types.
Declarations as ‘INPUT_0’= %IX0.0.2, ‘RESULT = %MD1234’
makes INPUT_0 and RESULT be able to used instead of %IX0.0.2
and %MD123 in programming.
GMWIN A peripheral device for the GLOFA-GM series. It executes program
creation, edit, compile and debugging.
FAM Abbreviationof the word ‘Factory Automation Monitoring S/W’. It is
used to call S/W packages for process supervision.
Task It means startup conditions for a program. There are three types of periodic task, internal contact task and external contact task
which starts by the input signals of external input modules.

Chapter 1. INTRODUCION
1 -4
Terms Definition Remarks
Sink Input
Current flows from the switch to the PLC input terminal if a input signal
turns on.
Source
Input
Current flows from the PLC input terminal to the switch after a input signal
turns on.
Sink Output
Current flows from the load to the output terminal and the PLC output turn
on.
Source
Output
Current flows from the output terminal to the load and the PLC output turn
on.
Fnet Fieldbus Network
Cnet Computer Network
Output
contact
Outputcontact

Chapter 2. SYSTEM CONFIGURATION
2 -1
Chapter 2. SYSTEM CONFIGURATION
The GLOFA-GM6 series has various modules suitable to configuration of the basic, computer link and network
systems.
This chapter describes the configuration and features of each system.
2.1 Overall Configuration
The following shows the overall configuration of the GLOFA-GM6series.
GM6-PAFA
PO
GM6-CPUA
RUN
STOP
RUN
PAU/REM
STOP
CPUModule
Battery
RS-232C
Cable
GMWIN
Power Supply
Module
(GM6-PAF□)
Baseboard(GM6-B0□M)
Discket
G6I-D22B
Input Module
(G6I-□□□□)
G6I -RY2A
Output Module
(G6Q-□□□A)
G6F -AD2A
Special Module
(G6F-□□□□)
G6L -FUEA
Communication
Module
(G6L-□□□□)
GMW
IN

Chapter 2. SYSTEM CONFIGURATION
2 -2
2.2 Product List
Thefollowingtableshows product list of GLOFA-GM6series.
2.2.1 GM6series Configuration
ItemsModelsDescription Remarks
GM6-CPUA •Maximum I/O points: 256
•Special functions : RS-232 communication
GM6-CPUB •Maximum I/O points :
•Special functions : RS-422/485 communication, RTC, PIDCPUmodule
GM6-CPUC •Maximum I/O points :
•Special functions : RS-232C communication, RTC, PID, HSC
G6I-D21A•8-point 12/24 VDC input module(current source& sink input)
G6I-D22A •16-point 12/24 VDC input module(current source& sink input)
G6I-D22B •16-point 12/24 VDC inputmodule(current source input)
G6I-D24A •32-point 12/24 VDC input module(current source& sink input)
G6I-D24B •32-point 12/24 VDC input module(current source input)
G6I-A11A•8-point 110 VAC input module
Digital input module
G6I-A21A•8-point 220 VAC input module
G6Q-RY1A•8-pointrelayoutputmodule(2A)
G6Q-RY2A •16-pointrelayoutputmodule(2A)
G6Q-TR2A •16-point transistor output module(0.5A, sink output)
G6Q-TR2B•16-point transistor output module(0.5A, source output)
G6Q-TR4A •32-point transistor output module(0.1A, sink output)
G6Q-TR4B•32-point transistor output module(0.1A, sourceoutput)
Digital output module
G6Q-SS1A•8-point triac output module(1A)
GM6-B04M •Upto 4 I/O modules can be mounted.
GM6-B06M •Upto6I/O modules can be mounted.Mainbaseunit GM6-B08M •Upto8I/O modules can be mounted.
GM6-PAFA•5 VDC : 2A, 24 VDC : 0.3A
GM6-PAFB
Free Voltage
(100 ~
240VAC) •5 VDC : 2A
•+15VDC : 0.5A, -15VDC:0.2A
GM6-PD3A DC24V
Power supply module
GM6-PDFA DC12/24V •5 VDC : 2A

Chapter 2. SYSTEM CONFIGURATION
2 -3
ItemsModelsDescription Remarks
A/Dconversion
module G6F-AD2A •Voltage/current input : 4 channels
•DC -10 to 10V / DC -20 to 20 mA
G6F-DA2V •Voltage output :4channels
•DC -10 to 10V D/Aconversion
module G6F-DA1A •Currentoutput :4channels
•DC 4 to 20 mA
Highspeed
counter module G6F-HSCA •Counting range: 0 to 16,777,215(24 bit binary)
•50 kHz, 1 channel
Special modules
Positioning
module G6F-POPA •Pulse output, 2-axes control
Fnet I/F module G6L-FUEA •For Fnet I/F
•1 Mbps base band
•For twisted cable
Fnet remote I/F
module G6L-RBEA •ForFnet remote I/F
•1 Mbps base band
•For twisted cable
G6L-CUEB•RS-232C
Computer Link
module G6L-CUEC•RS422
G6L-DUEA •Dnet I/Fmaster module
•Complying with ODVA (Open Devicenet
Vendor Association) 2.0 standard.
G6L-DSIA
•Dnet I/Fslave input module
•12/24 VDC input (16 points)
•Complying with ODVA (Open Devicenet
Vendor Association)2.0standard.
Communication
modules
Dnet I/F module
G6L-DSQA
•Dnet I/Fslave output module
•Relayoutput(16points)
•Complying with ODVA (Open Devicenet
Vendor Association) 2.0 standard.
Others DustProof
Module GM6-DMMA •Protect empty slot for dust

Chapter 2. SYSTEM CONFIGURATION
2 -4
2.3 System Configuration Types
System configuration is classified into 3 types that Basic system, Computer link system executing data
communications between the CPU module and a computer by use of a computer link module(G6L-CUEB/C )and
Network systemcontrollingthe PLC and remote I/O modules.
2.3.1 Basic System
The following describes basic system.
Example of System configuration
(The above figure shows the configuration where 16-input/output
modules are loaded.)
Maximum number of Input/Output modules 8 modules
Maximum number of Input/Output points •
16-point modulemounted:128 points
•32-point modulemounted:256 points
CPUmodule
GM6-CPUA,GM6-CPUB,GM6-CPUC
Power Supply module
GM6-PAFA,GM6-PAFB,GM6-PD3A,GM6-PDFA
BasicBaseUnit
GM6-B04/06/08M
I/O module G6I-
G6Q-
Special module G6F-
Configurationunits
Communication
module
G6L-
I/O number allocation
64pointsare allocatedtoeachslotin abaseboardwhateveritisemptyornot.
There'snolimitationforthelocationand thenumberofspecialmodulesonbaseboard.
Specialmodulesdonot have fixed I/OnumberswhileafixedI/O number is allocatedto
adigitalI/Omodule.
Adedicatedfunctionblockcontrols aspecialmoduleandmemory isallocated
automatically.
Note for power supply module selection •TouseA/D,D/Aconversionmodule,besuretoselectGM6-PAFBpowersupply
modulethatsupplies±15VDCinsteadof24VDC.±15VDC power is need for operation
ofinternalanalog circuitofA/Dand D/Aconversionmodules.
BaseBoard
POWER CPU
0.0.0
~
0.0.15
0.1.0
~
0.1.15
0.2.0
~
0.2.15
0.3.0
~
0.3.15
0.4.0
~
0.4.15
0.5.0
~
0.5.15
0.6.0
~
0.6.15
0.7.0
~
0.7.15
Slot number 0 1 2 3 4 5 6 7

Chapter 2. SYSTEM CONFIGURATION
2 -5
2.3.2 Computer Link System
Computer Link System communicates data between the CPU module and peripheral devices like a
computer or a printer by use of RS-232CandRS-422(or RS-485)interfaceofthecomputerlinkmodule.
The G6L-CUEB or G6L-CUEC are the computer link module for GM6series. For details of computer link
module, refer to related User's Manual.
2.3.3 Network System
The Network system adapted in the GLOFA series a Fnet system that satisfies the IEC/ISA field bus
specifications. Fnet system as a network system is used for data communications between CPU modules
and control of remote I/O modules so that distribution of control and concentration of supervision could be
easy. For details, refer to Fnet system user's manual.

Chapter 3. GENERAL SPECIFICATIONS
3 -1
Chapter 3. GENERAL SPECIFICATION
3.1 General specifications
The following shows the general specifications of the GLOFA-GM series.
No Item Specifications References
1Operatingambient
temperature 0 ~ 55 °C
2Storageambient
temperature -25 ~ +75°C
3Operatingambient
humidity 5 ~ 95%RH, non-condensing.
4Storage ambient
humidity 5 ~ 95%RH, non-condensing.
Occasional vibration
Frequency Acceleration Amplitude Sweep count
10≤f<57 Hz -0.075mm
57≤f≤150 Hz 9.8 m/s 2{1G} -
Continuous vibration
Frequency Acceleration Amplitude
10≤f <57 Hz -0.035mm
5Vibration
57≤f≤150 Hz 4.9 m/s2{0.5G} -
10 times per
a
xis,
on X,Y, Z axis
IEC 1131-2
6Shocks Maximum shock acceleration: 147 m/s2{15G}
Duration time:11ms
Pulse wave: half sine pulse (3 shocks per axis, on X,Y,Z axis) IEC 1131-2
Squarewave
Impulse Noise ±1,500 V
Electronic
discharge Voltage : 4 kV IEC 1131-2, IEC 801-3
Radiated
electromagneticfield
noise 27 ~ 500 MHz,10V/m IEC 1131-2,
IEC 801-3
Item Power
supply DigitalI/O (>24V)
Digital I/O
(<24V)
Analog I/O
interface
IEC 1131-2,
IEC 801-4
7Noise Immunity
Fasttransient/burst
noise
Voltage 2 kV 1 kV 0.25 kV
8Operating
ambience Free of corrosive gases and excessivedust. IEC 1131-2
9Altitude 2,000 m or less
10 Pollution 2
11 Cooling method Air-cooling
REMARK
1) IEC(InternationalElectromechanical Commission) : An international civilian institute who establishes
international standards in area of electric's and electronics.
2)Pollution : An indicator which indicates pollution degree which determine insulation performance of equipment.
Pollution 2 means that non-conductive pollution usually occurs but temporal conduction occurs with condensing

Chapter 4. CPU module
4 -1
Chapter 4. CPU MODULE
4.1 Performance specifications
The following shows the general specifications of the GLOFA-GM series.
Specifications
Items
GM6-CPUA
GM6-CPUB
GM6-CPUC
Remarks
Operationmethod Cyclicoperationofstoredprogram,Interrupt taskoperation
I/Ocontrolmethod Scansynchronized batchprocessingmethod(Refreshmethod)
Programminglanguage LadderDiagram(LD) InstructionList(IL)
SequentialFunctionChart(SFC)
Operator LD : 13, IL : 21
Basicfunction 194
Basicfunctionblock 11
Numberof
instructions
Specialfunctionblock Each special module havetheir own special function blocks
Operator
Basicfunction
Processing
speed Basicfunctionblock RefertoAppendix3.
Programmingmemorycapacity 68kbytes(17ksteps)
I/Opoints 256points
Directvariablearea 2to8kbytes
Datamemory Symbolicvariablearea 30kbytes–Directvariablearea
Timer Nolimitationsinpoints.
Timerange:0.01to4294967.29sec(1193hours) 1pointoccupies20bytes ofsymbolicvariablearea.
Counter Nolimitationsinpoints
Countingrange:-32768to+32767 1pointoccupies8bytes ofsymbolicvariablearea.
Numbersofprogramblocks 100
Initializationprograms 1(_INIT)
Timedriventasks 0~8
Externalinterrupttasks 0~8
Program
types Task
Programs Internal task 0~8
Total:8
(Thetypeoftaskis
variable,however,total
numbersoftasksis8.)
Operationmodes RUN,STOP,PAUSEandDEBUG
Restartmodes Cold,Warm
Self-diagnosticfunctions Watchdogtimer,Memoryerror detection,I/Oerrordetection, Battery
errordetection,Powersupplyerrordetection,etc.
Dataprotectionmethodatpowerfailure Setto'Retain'variablesatdatadeclaration.
Built-inspecialfunctions RS-232C RS-422/485
RTC
PIDcontrol
RS-232C
RTC
PIDcontrol
HighSpeedCounter
Internalcurrentconsumption 170mA 210mA 170mA
Weight 0.11Kg 0.11Kg 0.12Kg

Chapter 4. CPU module
4 -2
4.2 Operation Processing
4.2.1 Operation Processing Method
1) Cyclicoperation
A PLC program is sequentially executed from the first step to the last step, which is called scan.
This sequential processing is called cyclic operation. Cyclic operation of the PLC continues as long as
conditionsdonotchange for interrupt processing during programexecution.
This processing is classified into the following stages.
Stages Processing
-
•Stage for the start of a scan processing. it is executed only one time when
the power is applied or reset is executed. It executes the following processing.
4I/O modules reset 4Executionof self-diagnosis
4Data clear 4I/O module address allocation or type registration
•Input module conditions are read and stored into the input image area before
operation processing of a program.
•Program is sequentially executed from the firststepto the laststep
•The contents stored in the output image area is output to output modules when
operation processing of a program is finished.
•Stage for return processing after the CPU module has finished 1 scan. The
following processing are executed.
4Self-diagnosis
4Change of the present values of timer and counter, etc.
4Processing data communications between computer link module and
communications module.
4Checking the switch for mode setting.
Initialization
Input image area refresh
Program operation processing
Program start
~
Program end
Output image area refresh
ENDprocessing
OperationStart

Chapter 4. CPU module
4 -3
2) Time driven interrupt operationmethod
In time driven interrupt operation method, operations are processed not repeatedly but at every pre-set interval.
Interval, in the GM6CPU module, can be set to between 0.01 to 4294967.29 sec. This operation is used to
process operation withaconstantcycle.
3) Eventdriveninterruptoperationmethod
If a situation occurs which is requested to be urgently processed during execution of a PLC program, this
operation method processes immediately the operation which corresponds to interrupt program. The signal
which informs the CPU module of those urgent conditions is called interrupt signal. The GM6CPU module has
two kind of interrupt operation methods, which are internal and external interrupt signal methods.
4.2.2 Operation processing atmomentary powerfailure occurrence
The CPU module detects any momentary power failure when the input line voltage to the power supply
module falls down below the defined value.
When the CPU module detects any momentary power failure, the following operations will be executed.
1) Momentary power failure within 20 ms
(1)Theoperationprocessingisstoppedwiththeoutputretained.
(2)Theoperation processing isresumedwhennormalstatus isrestored.
(3)Theoutputvoltageofthepowersupplymoduleretainsthedefinedvalue.
(4) The watch dog timer(WDT) keeps timing and interrupt timing normally
whiletheoperationsisata stop.
2) Momentary power failure exceeding 20 ms
•There-startprocessingisexecutedasthepowerisapplied.
REMARK
1)Momentary powerfailure
The PLC defining power failure is a state that the voltage of power has been lowered outside the allowable variation
range of it. The momentary power failure is a power failure of short interval(several to tens ms).

Chapter 4. CPU module
4 -4
4.2.3 ScanTime
Theprocessingtimefroma0steptothenext0stepiscalledscan time.
1) Expression for scan time
Scan time is the addition value of the processing time of scan program that the user has written, of the task program
processing time and the PLC internal processing time.
(1)Scantime=Scan program processing time+Taskprogramprocessingtime + PLC internalprocessingtime
•Scanprogramprocessing time=Theprocessingtime usedtoprocessauser programthatisnotspecified toataskprogram.
•Taskprogramprocessing time=Totalof theprocessingtimesof taskprogramsexecutedduringonescan.
•PLC internal processing time = Self-diagnosis time + I/O refresh time + Internal data processing time + Communications
serviceprocessingtime
(2)Scantimediffersinaccordancewiththeexecutionornon-executionoftaskprogramsandcommunicationsprocessing,etc.
2)Flag
(1) Scan time is storedinthe following system flag area.
•_SCAN_MAX:Maximumscantime(unit:1ms)
•_SCAN_MIN:Minimum scantime(unit: 1ms)
•_SCAN_CUR:Currentscan time(unit: 1ms)
4.2.4 Scan Watchdog Timer
1)Watchdog timer is used to detect a delay of abnormal operation of sequence program.
(Watchdog time is set in menu of basic parameter of GMWIN.)
2)When watchdog timer detects an exceeding of preset watchdog time, the operation of PLC is stopped
Immediately and all output is off.
3)If an exceeding of preset watchdog time is expected in sequence program, use ‘WDT_RST’function.
‘WDT_RST’function make elapsedwatchdogtimeaszero.
4)In order to clear watchdog error, using manual reset switch, restarting the PLC and mode change to STOP
mode are available.
REMARK
Setting range of watchdog : 1 ~ 65,535ms( 1ms base )