Internal Relay Flags

This section goes over all the internal relay flags in MapleLogic such as execution modes, error codes, interval system clocks, and more.

Execution Mode Relay Flags (F000)

The execution mode flags, F000, are used to indicate the current operation mode of the PLC.
These flags provide critical status information for system monitoring and control.

Flag Bit	Name	Description	Use Case
F000.0	Run Mode	ON when the PLC is in RUN mode	Indicates the PLC is executing the program
F000.1	Stop Mode	ON when the PLC is in STOP mode	Indicates the PLC is not executing the program
F000.2	Pause Mode	ON when the PLC is in Pause mode	Helps identify temporary pauses in execution
F000.3	Debug Mode	ON when the PLC is in Debug mode	Assists with step-by-step program debugging
F000.7	Remote Mode	ON when the PLC is in Remote mode	Indicates control via a remote device or network
F000.F	Execute STOP Instruction	ON when the STOP instruction is executed	Used to confirm that a program STOP was issued

F000.0 – Run Mode

Description

The RUN Mode flag is ON (1) when the PLC is actively executing the program.
This indicates that the PLC is performing normal operations.

Use Case

Used to monitor if the PLC is operational and running the current program.
Essential for diagnostics when verifying system activity.

F000.1 – STOP Mode

Description

The STOP Mode flag is ON (1) when the PLC is NOT actively executing the program.
This indicates that the PLC is NOT performing normal operations.
This flag is ON (1) when the RUN/STOP switch is turned to STOP on the PLC.

Use Case

Used to confirm the PLC is ready for program modifications.
Prevents inadvertent program execution during updates.

F000.2 – Pause Mode

Description

The Pause Mode flag is ON (1) when the PLC is temporarily paused.
This halts execution without changing the program.

Use Case

Useful during debugging to pause execution and analyze specific states.
Allows for temporary halts without terminating the program.

F000.3 – Debug Mode

Description

The Debug Mode flag is ON (1) when the PLC is in debugging mode.
This enables step-by-step execution for testing and troubleshooting.

Use Case

Allows precise control over the program execution during testing.
Helps identify logic errors in the program.

F000.7 – Remote Mode

Description

The Remote Mode flag is ON (1) when the PLC is controlled via a remote device or network.
This is typically used in distributed or automated systems.
When the PLC is being monitored by the computer, this flag is ON (1).

Use Case

Indicates the PLC is under remote supervision or operation.
Helps monitor network-based control operations.

F000.F – Executes STOP Instruction

Description

The Execute STOP Instruction flag is ON (1) when the PLC executes the STOP instruction.
This halts the current program.
The PLC RUN/STOP mode is changed from RUN→STOP when the STOP instruction is executed.
As a result, the STOP Mode flag (F0.1) is ON (1).

Use Case

Confirms that a STOP instruction has been issued in the program.
Can be used as part of safety protocols to ensure proper shutdown.

First Scan Relay Flags (F001)

The first scan flags, F001, provide initialization statuses during the first scan of the PLC after a program start or reset.
These flags are commonly used to initialize variables, settings, or other logic components in a predictable way at the start of program execution.

Flag Bit	Name	Description	Use Case
F001.0	Always ON	This flag is always ON (1)	Used for triggering logic that should always execute
F001.1	Always OFF	This flag is always OFF (0)	Used for disabling specific conditions or logic paths
F001.2	ON at First Scan Only	This flag is ON (1) only during the first scan after the program starts or resets	Useful for initializing variables or settings at program start
F001.3	OFF at First Scan Only	This flag is OFF (0) only during the first scan after the program starts or resets	Used to prevent execution during initialization
F001.4	Toggle at Each Scan	Toggles between ON (1) and OFF (0) at each scan	Used for timing logic or alternating states

F001.0 – Always ON

Description

The Always ON flag is ON (1) regardless of the program execution or conditions.

Use Case

Used as a base condition to ensure specific logic or actions are always executed.
Can serve as a default true condition in ladder logic or other control processes.

F001.1 – Always OFF

Description

The Always OFF flag is OFF (0) regardless of the program execution or conditions.

Use Case

Useful for logic paths or operations that should never trigger.
Can disable unused parts of logic for testing or development.

F001.2 – ON at First Scan Only

Description

The ON at First Scan Only flag is ON (1) only during the first scan after a program starts or resets.
After the first scan, this flag remains OFF (0).

Use Case

Initializes variables, counters, timers, or settings during startup.
Used to reset program states or trigger setup routines.

F001.3 – OFF at First Scan Only

Description

The OFF at First Scan Only flag is OFF (0) only during the first scan after a program starts or resets.
After the first scan, this flag remains ON (1).

Use Case

Used to delay certain operations or logic until after initialization is complete.
Helps prevent unintended execution during the first program cycle.

F001.4 – Toggle at Each Scan

Description

The Toggle at Each Scan flag alternates between ON (1) and OFF (0) with each scan cycle.

Use Case

Ideal for creating alternating states or timing events.
Can be used for blinking indicators or flip-flop logic.

Error Relay Flags (F003)

The module error flags, F003, indicate error states and warnings in the PLC.
These flags assist in diagnosing issues, monitoring system performance, and responding to critical system states.

Flag Bit	Name	Description	Use Case
F003.0	Error (Major Error)	ON (1) during any error condition	Used to monitor the system for active errors
F003.1	Warning (Minor Error)	ON (1) during warning conditions	Used to identify non-critical error warnings
F003.2	Watchdog Timer Error	ON (1) when a watchdog timer error occurs	Used to handle program execution timeout errors
F003.3	I/O Error	ON (1) during I/O combined errors	Helps detect hardware or communication issues
F003.4	Battery Low	ON (1) when the battery voltage is below the threshold	Used to prompt battery replacement
F003.5	Forced ON/OFF	ON (1) when forced ON/OFF is applied to I/O points	Monitors overrides or forced settings

F003.0 – Error (Major Error)

Description

The Error (Major Error) flag is ON (1) during any error condition in the system.

Use Case

Monitor the system for active errors.
Trigger alarms or notifications to alert operators of system issues.

F003.1 – Warning (Minor Error)

Description

The Warning (Minor Error) flag is ON (1) during non-critical warning conditions.

Use Case

Identify warning signals that require attention but are not critical to operation.
Can be used to plan maintenance or check system health.

F003.2 – Watchdog Timer Error

Description

The Watchdog Timer Error flag is ON (1) when a watchdog timer error occurs.
This is typically caused by program execution delays or system overloads.

Use Case

Detect program execution timeouts.
Initiate recovery actions to prevent system hangups.

F003.3 – I/O Error

Description

The I/O Error flag is ON (1) during input or output combined errors like communication or hardware failures.

Use Case

Diagnose issue in input/output modules.
Trigger fault routines or safety mechanisms.

F003.4 – Battery Low

Description

The Battery Low flag is ON (1) when the PLC’s battery voltage drops below the acceptable threshold.

Use Case

Prompt timely battery replacement.
Prevent loss of data stored in volatile memory.

F003.5 – Forced ON/OFF

Description

The Force ON/OFF flag is ON (1) when forced ON/OFF settings are applied to any I/O points.

Use Case

Monitor overrides or forced operations.
Ensure that overrides are intentional and controlled.

I/O Errors Relay Flags (F004)

Flag Bit	Name	Description	Use Case
F004.0 ~ F004.7	I/O Error (Slot Storage)	ON (1) if the reserved I/O and physical chassis I/O are different Number of differing slots (0 ~ 11) is stored	Used to identify and resolve slot-based configuration mismatches
F004.8 ~ F004.F	I/O Error (Expansion Storage)	ON (1) if the reserved I/O and physical chassis I/O are different Number of differing expansions (0 ~ 11) is stored	Used to identify and resolve mismatches in expansion modules

F004.0 ~ F004.7 – I/O Error (Slot Storage)

Description

The I/O Error (Slot Storage) flag is ON (1) when the reserved I/O configurations differ from the physically mounted chassis I/O configuration.
The range of differing slots stored is 0 ~ 11.

Use Case

Detect and resolve slot-based mismatches in I/O configurations.
Ensure that all reserved slots match the physical hardware setup.

F004.8 ~ F004.F – I/O Error (Expansion Storage)

Description

The I/O Error (Expansion Storage) flag is ON (1) when the reserved I/O configurations differ from the physically mounted chassis I/O configuration.
The range of differing expansions stored is 0 ~ 11.

Use Case

Identify mismatches in connected expansion modules.
Ensure expansion configurations align with the program’s reserved setup.

Error Code Internal Relay Flag (F005)

The interval relay, F005, will be ON if any of the below CPU errors occur.

CPU Error Code – 0x0100

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0101	RAM Fault	STOP	Off	Blinking	Hardware failure. Replace CPU module.
0x0102	Flash Memory Fault	STOP	Off	Blinking	Hardware failure. Replace CPU module.
0x0103	User Program Error (RAM)	STOP	Off	Blinking	Delete the current program. Power cycle the PLC. Download the program again. If the issue still persists, replace the CPU module.
0x0104	User Program Error (Flash Memory)	STOP	Off	Blinking	Delete the current program. Power cycle the PLC. Download the program again. If the issue still persists, replace the CPU module.
0x0105	Parameter PBT Checksum Error	STOP	Off	Blinking	Delete the current program. Power cycle the PLC. Download the program again. If the issue still persists, replace the CPU module.
0x0106	Flash Data Error Backup Data Load Fail (BP)	STOP	Off	Blinking	Download the program again. Power cycle the PLC. If the issue still persists, replace the CPU module.
0x0107	ROM Pack Program Error Load Failure	STOP	Off	Blinking	Download a new program or delete the existing program. Power cycle the PLC. If the PLC connection is unavailable, remove the ROM pack from the CPU after powering off. The CPU will operate in RAM mode.
0x0108	Parameter Checksum Error	STOP	Off	Blinking	Download the program or project again. If the issue still persists, replace the CPU module.
0x0109	PBT Checksum Error	STOP	Off	Blinking	Download the program or project again. If the issue still persists, replace the CPU module.
0x010A	User Program Checksum Error	STOP	Off	Blinking	Download the program or project again. If the issue still persists, replace the CPU module.

CPU Error Code – 0x0200

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0201	RTC Data Failure	RUN	ON	Off	RTC error in CPU module. Contact Maple Systems if issue persists.
0x0202	RTC Data Failure (Sub)	RUN	ON	Off	RTC error in CPU module. Contact Maple Systems.
0x0203	WDT Timeout	STOP	OFF	Blinking	Modify the program to NOT go over the watchdog timer value or change the watchdog timer PLC parameter. Reset the PLC mode after modification.
0x0204	CPU WDT Occurrence	STOP	OFF	Blinking	The watchdog timer occurred during CPU operation. Contact Maple Systems if issue persists.
0x0205	Battery Fault (Low Voltage)	RUN	ON	Blinking	Low voltage or dead battery. Change the PLC battery.
0x0206	ASIC STOP1	STOP	OFF	Blinking	Contact Maple Systems if issue persists.
0x0207	ASIC STOP2	STOP	OFF	Blinking	Contact Maple Systems if issue persists.
0x0208	ASIC STOP3	STOP	OFF	Blinking	Contact Maple Systems if issue persists.
0x0209	Scan Program Timeout	STOP	OFF	Blinking	Timeout occurred during scan program operation. Contact Maple Systems if issue persists.

CPU Error Code – 0x0300

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0301	Base Type Mismatched with Reservation	STOP	Off	Blinking	Set the base and parameter identically. Power cycle the PLC.
0x0302	Module Dismount during RUN Mode	STOP	Off	Blinking	Check the installation of the module from the F007 flag. Power cycle the PLC.
0x0303	Module Type Reservation Error	STOP	Off	Blinking	Check the installation of the module from the F007 flag. Modify the base and slot number identically with the module installation. Power cycle the PLC.
0x0304	I/O Reservation Setting Error	STOP	Off	Blinking	Reserved I/O or installed I/O modules exceed the CPU capacity. Decrease the I/O count or upgrade the CPU module.
0x0305	Expansion Module Reset Failure	RUN/STOP	On/Off	Blinking	Hardware failure of the expansion module. Reset the error. Contact Maple Systems support if the issue still persists.
0x0306	Expansion Module System Data Read/Write Failure	RUN/STOP	On/Off	Blinking	`Reset the PLC mode.` Examine the operating environment. There is a possibility of external noise.
0x0307	Expansion Module User Data Read/Write Failure	RUN/STOP	On/Off	Blinking	Hardware failure of the expansion module. Replace the expansion module.
0x0308	No Response from Expansion Base	STOP	Off	Blinking	Check if the number of expansion bases are the same with the current PLC configuration. Check if the DIP switch is set correctly. Reset the PLC mode. Examine the operating environment. There is a possibility of external noise.
0x0309	Receive Data Error in Expansion Communication	STOP	Off	Blinking	Transmitted data from the expansion module can be corrupted. Power cycle the PLC.
0x030A	I/O Error in Expansion Communication	STOP	Off	Blinking	I/O error code received from the expansion module. Power cycle the PLC.
0x030B	NAK Received in Expansion Communication	STOP	Off	Blinking	Response failure from expansion module. Power cycle the PLC.
0x030C	FROM/TO Instruction Base/Slot Error	RUN/STOP	On/Off	Blinking	There is no module at the base/slot where the FROM/TO instructions is assigned. Examine the operating environment. There is a possibility of external noise. Hardware failure of the expansion module. Replace the expansion module.
0x030D	Duplicated Redundancy Module	STOP	Off	Blinking	Remove the duplicated redundancy module.
0x030E	Digital Output Failure	RUN/STOP	On/Off	Blinking	Hardware failure of the expansion module. Replace the expansion module.
0x030F	Timeout of CPU Instruction	STOP	Off	Blinking	Expansion module hasn’t received any commands from the CPU for certain time. Power cycle the PLC.
0x0310	Expansion Module User Data Read/Write Failure	STOP	Off	Blinking	Failed to read/write user data to the expansion module. Power cycle the PLC.
0x0311	No Response from Expansion Module User Data Read/Write	STOP	Off	Blinking	There is no response from the expansion module after the execution of the user data read/write command. Examine the operating environment. There is a possibility of external noise. Reset the PLC Mode.
0x0312	Wrong Redundancy Module Switch Setting	STOP	Off	Blinking	The switch setting on the redundancy MMI module may be wrong. Differentiate switches as primary and secondary. Set the power.
0x0313	Expansion Module Data Read/Write Failure	STOP	Off	Blinking	Failed to read/write data to the expansion module. Power cycle the PLC.
0x0314	Mount Error of Module in Expansion Base	STOP	Off	Blinking	A module on the expansion base may have been installed or dismounted during RUN mode. Check the installation status. Power cycle the PLC.
0x0315	Unknown CPU Module Detected	RUN/STOP	On/Off	Blinking	Replace the current CPU module with the correct CPU module.
0x0316	Duplicate Starting Base Address	STOP	Off	Blinking	The starting address from the base is duplicated Check the I/O reservation settings. Download the project again.
0x0317	Exceeded IO-SD0016R/IO-SD0808R Amount	STOP	Off	Blinking	More than a combination of 4 IO-SD0016R or IO-SD0808R modules are installed. Remove the additional modules. Power cycle the PLC.
0x0318	CPU and Expansion Base Connection Error	STOP	Off	Blinking	Check the connection status of the expansion base. Power cycle the PLC.

CPU Error Code – 0x0400

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0401	User Program Compile Error	STOP	Off	Blinking	Check the information of the PLC project file, PLC CPU firmware version, and the MapleLogic version.
0x0402	User Program Exceeds Step Maximum	STOP	Off	Blinking	Decrease the number of steps in the program. Change the CPU module with one that allows for more steps.
0x0403	Error in Reading or Writing to D Data Register	STOP	Off	Blinking	Check the D data register range allowed by the CPU.
0x0404	FOR/NEXT Syntax Error	STOP	Off	Blinking	Modify the use of the FOR and NEXT instructions.
0x0405	JUMP/CALL Syntax Error	STOP	Off	Blinking	Modify the use of the JUMP and CALL instructions.
0x0406	JME/SBRT Index Exceeds 127	STOP	Off	Blinking	Ensure the value of the JME and SBRT instructions does NOT exceed 127.
0x0407	Duplicate JME/SBRT Index	STOP	Off	Blinking	Ensure the value of the JME and SBRT instructions are NOT duplicates.
0x0408	Invalid Location of JME Instruction	STOP	Off	Blinking	Modify the JME instruction to be in the correct location. Compile the modified program.
0x0409	Invalid Location of JUMP Instruction	STOP	Off	Blinking	Modify the JUMP instruction to be in the correct location. Compile the modified program.
0x040A	SBRT Nesting Error	STOP	Off	Blinking	The SBRT instruction must be used inside a subroutine program. Remove the SBRT from the scan program.
0x040B	No RET Instruction Found in Subroutine	STOP	Off	Blinking	Add the RET instruction to the subroutine program. Compile the modified program.
0x040C	FOR Loop Amount Exceeds 20	STOP	Off	Blinking	Ensure there are 20 or less FOR loops.
0x040D	Base/Slot Number in Special Program Mismatch	STOP	Off	Blinking	Set the correct base/slot number of expansion modules in the special program correctly. Compile the modified program.
0x040E	Duplicate High-Speed Counter Program	STOP	Off	Blinking	Remove the duplicate high-speed counter program. Compile the modified project.
0x040F	Duplicate Positioning Program	STOP	Off	Blinking	Remove the duplicate positioning program. Compile the modified project.
0x0410	Duplicate Communication Program	STOP	Off	Blinking	Remove the duplicate high-speed Ethernet link program. Compile the modified project.
0x0411	Duplicate PID Program	STOP	Off	Blinking	Remove the duplicate PID program. Compile the modified project.
0x0412	Duplicate Web Server Program	STOP	Off	Blinking	Remove the duplicate web server program. Compile the modified project.
0x0413	Duplicate Security Program	STOP	Off	Blinking	Remove the duplicate security program. Compile the modified project.

CPU Error Code – 0x0500

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0501	Invalid Instruction	STOP	Off	Blinking	Replace the current CPU with the latest model.
0x0502	Exceed CALL Level	STOP	Off	Blinking	Modify the program to fix the error. Compiled the modified program.
0x0503	@D Out of Range	STOP	Off	Blinking	Modify the program to fix the error. Compiled the modified program.
0x0504	No Scan Program	STOP	Off	Blinking	Download the scan program. Reset the PLC mode.
0x0505	Invalid Data Register Memory Accessed	STOP	Off	Blinking	Ensure the data register maximum value is used correctly. Compile the modified program.
0x0506	FREAD/FWRITE Overuse	STOP	Off	Blinking	Too many FREAD and FWRITE instructions are used at the same time. Maximum 200 FREAD/FWRITE instructions can be used.
0x0507	No Expansion Module at Instruction for Expansion Module	STOP	Off	Blinking	FROM, TO, SEND, RECV, SND, RCV, FREAD, FWRITE Modify the instruction to call the correct module. Compile the modified program.
0x0508	Expansion Module Instruction Overuse	STOP	Off	Blinking	POSCTRL, TEACHn, PSTRTn, WGBATCH Too many instructions are used at the same time. Modify the program to call less instructions. Compile the modified program.
0x0509	Multiple Actions of Interrupt	STOP	Off	Blinking	Too many interrupts are used at the same time. Modify the project to use less interrupts. Compile the modified program.
0x050A	Wrong Program ID (PID)	STOP	Off	Blinking	Incorrect program ID input into an instruction. Modify the program to call the correct program ID. Compile the modified program.
0x050B	Index Error in Timer	STOP	Off	Blinking	Check if the timer instruction is duplicated. Modify the program to remove the duplicated timer instruction. Compile the modified program.
0x050C	File System Error in SD Card	STOP	Off	Blinking	File system error occurred during web server operation. Backup or replace the SD card.
0x050D	SD Card Error	STOP	Off	Blinking	SD card error occurred during web server operation. Replace the SD card.

CPU Error Code – 0x0600

Code	Error	CPU	LED RUN	LED STOP	Troubleshooting
0x0601	SFC Implementation Timeout	RUN	Off	Blinking	A timeout occurred in a sequential function chart transition condition. Modify the sequential function chart implementation time.
0x0602	No Web Server Program	RUN	Off	Blinking	There is no web server program in the current project. Add a web server program to the project.
0x0603	No Security Program	RUN	Off	Blinking	There is no security program in the current project. Add a security program to the project.

RAM Errors Relay Flags (F007)

Flag Bit	Name	Description	Use Case
F007.0 ~ F007.7	RAM Error (Slot Storage)	ON (1) if Dual Port RAM access errors occur for a slot Number of differing slots (0 ~ 11) is stored	Diagnose and resolve slot-based Dual Port RAM errors
F007.8 ~ F007.F	RAM Error (Expansion Storage)	ON (1) if Dual Port RAM access errors occur for expansions Number of differing expansions (0 ~ 11) is stored	Diagnose and resolve expansion-related Dual Port RAM errors

F007.0 ~ F007.7 – I/O Error (Slot Storage)

Description

The RAM Error (Slot Storage) flag is ON (1) when the reserved I/O configurations differ from the physically mounted chassis I/O configuration.
The range of differing slots stored is 0 ~ 11.

Use Case

Detect and resolve slot-based mismatches in I/O configurations.
Ensure that all reserved slots match the physical hardware setup.

F007.8 ~ F007.F – I/O Error (Expansion Storage)

Description

The RAM Error (Expansion Storage) flag is ON (1) when the reserved I/O configurations differ from the physically mounted chassis I/O configuration.
The range of differing expansions stored is 0 ~ 11.

Use Case

Identify mismatches in connected expansion modules.
Ensure expansion configurations align with the program’s reserved setup.

Interval System Clocks Relay Flag (F009)

Flag Bit	Name	Description	Use Case
F009.0	0.02s	This flag toggles ON (1) and OFF (0) every 0.02 seconds	Used for high-frequency timing operations
F009.1	0.1s	This flag toggles ON (1) and OFF (0) every 0.1 seconds	Ideal for short-interval process monitoring
F009.2	0.2s	This flag toggles ON (1) and OFF (0) every 0.2 seconds	Suitable for mid-range timing applications
F009.3	1s	This flag toggles ON (1) and OFF (0) every 1 seconds	Commonly used for second-based operations
F009.4	2s	This flag toggles ON (1) and OFF (0) every 2 seconds	Used for slower timing or periodic processes
F009.5	10s	This flag toggles ON (1) and OFF (0) every 10 seconds	Ideal for low-frequency repetitive tasks
F009.6	20s	This flag toggles ON (1) and OFF (0) every 20 seconds	Suitable for monitoring or logging intervals
F009.7	1m	This flag toggles ON (1) and OFF (0) every 1 minute	Used for long-term periodic operations

F009.0 – 0.02s

Description

The 0.02s internal system clock flag is ON (1) and OFF (0) every 0.02 seconds during RUN mode.

Use Case

Suitable for high-frequency timing operations.
Used for tasks requiring precise time intervals, such as fast data sampling.

F009.1 – 0.1s

Description

The 0.1s internal system clock flag is ON (1) and OFF (0) every 0.1 seconds during RUN mode.

Use Case

Used for short-duration event monitoring.
Ideal for process control tasks with quick response times.

F009.2 – 0.2s

Description

The 0.2s internal system clock flag is ON (1) and OFF (0) every 0.2 seconds during RUN mode.

Use Case

Useful for medium-duration timing needs.
Can be applied to repetitive mid-range tasks.

F009.3 – 1s

Description

The 1s internal system clock flag is ON (1) and OFF (0) every 1 second during RUN mode.

Use Case

Commonly used for time-sensitive periodic operations.
Suitable for creating a basic 1-second timer.

F009.4 – 2s

Description

The 2s internal system clock flag is ON (1) and OFF (0) every 2 seconds during RUN mode.

Use Case

Used for slower periodic events.
Ideal for tasks that require actions every 2 seconds.

F007.8 ~ F007.F – I/O Error (Expansion Storage)

Description

The 10s internal system clock flag is ON (1) and OFF (0) every 10 seconds during RUN mode.

Use Case

Suitable for low-frequency repetitive tasks.
Can be used for logging or monitoring operations at 10-second intervals.

F007.8 ~ F007.F – I/O Error (Expansion Storage)

Description

The 20s internal system clock flag is ON (1) and OFF (0) every 20 seconds during RUN mode.

Use Case

Ideal for longer periodic tasks.
Suitable for slower processes or system checks.

F007.8 ~ F007.F – I/O Error (Expansion Storage)

Description

The 1m internal system clock flag is ON (1) and OFF (0) every 1 minute during RUN mode.

Use Case

Ideal for long-duration periodic operations.
Commonly used for monitoring and logging tasks or as a clock signal for minute-based processes.

User Clocks Relay Flags (F010)

Flag Bit	Name	Description	Use Case
F010.0	User Clock 0	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.1	User Clock 1	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.2	User Clock 2	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.3	User Clock 3	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.4	User Clock 4	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.5	User Clock 5	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.6	User Clock 6	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks
F010.7	User Clock 7	User-configurable clock controlled by the DUTY instruction	Used for custom periodic tasks

F010.0 – User Clock 0

Description

The user clock 0 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.1 – User Clock 1

Description

The user clock 1 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.2 – User Clock 2

Description

The user clock 2 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.3 – User Clock 3

Description

The user clock 3 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.4 – User Clock 4

Description

The user clock 4 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.5 – User Clock 5

Description

The user clock 5 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.6 – User Clock 6

Description

The user clock 6 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

F010.7 – User Clock 7

Description

The user clock 7 flag is ON (1) and OFF (0) based on a user-defined value during RUN mode.

Use Case

Allows for custom timing in parallel operations.
Useful for managing time-sensitive processes.
Suitable for creating multi-clock systems in a single PLC.
Useful for asynchronous timing of processes.
Useful for timing individual subsystems or tasks.
Enables precise control over time-based operations.

Control Relay Flags (F011)

Flag Bit	Name	Description	Use Case
F011.0	Operation Error	ON (1) when an operation error occurs	Detect and respond to operation errors
F011.1	Zero	Indicates that the result of an operation is 0	Monitor 0 results in arithmetic operations
F011.2	Carry	Indicates a carry bit result from an arithmetic operation	Useful for overflow detection in calculations
F011.8	All Outputs OFF	ON (1) when all outputs are turned OFF	Verify complete shutdown of outputs
F011.9	DPRAM Access Error	Indicates a Dual Port RAM (DPRAM) access error Details are stored in the F007 flag	Diagnose DPRAM-related issues

F011.0 – Operation Error

Description

The operation error flag is ON (1) when an error occurs during a PLC operation.
This could be due to invalid instructions or incompatible operations.

Use Case

Detect operation errors in real time.
Trigger alarms or diagnostic routines to respond to faulty operations.

F011.1 – Zero

Description

The zero flag is ON (1) when the result of an arithmetic or logical operation equals zero.

Use Case

Monitor calculations to detect zero results.
Useful in conditional operations or error-checking logic.

F011.2 – Carry

Description

The carry flag is ON (1) when a carry bit is generated during arithmetic operations, indicating an overflow in the calculation.

Use Case

Detect overflow conditions during addition or subtraction.
Ensure accurate handling of arithmetic results.

F011.8 – All Outputs OFF

Description

The all outputs OFF flag is ON (1) when all output points of the PLC are deactivated.

Use Case

Verify complete shutdown of system outputs.
Monitor system safety during idle or maintenance states.

F011.9 – DPRAM

Description

The DPRAM error flag is ON (1) when there is an issue accessing the Dual Port RAM.
Additional details are stored in the F007 flags for more in-depth diagnostics.

Use Case

Diagnose issues with DPRAM access, such as read/write errors.
Trigger fault routines to handle memory access problems.

Comparison Relay Flag (F012)

Flag Bit	Name	Description	Use Case
F012.0	Less Than (<)	ON (1) when the result of an unsigned comparison is less than	Used to evaluate conditions where one value is less than another
F012.1	Less Than Equal To (≤)	ON (1) when the result of an unsigned comparison is less than or equal	Used to evaluate conditions where one value is less than or equal to another
F012.2	Equal (=)	ON (1) when the result of an unsigned comparison is equal	Used to evaluate conditions where one value is equal to another
F012.3	Greater Than (>)	ON (1) when the result of an unsigned comparison is greater than	Used to evaluate conditions where one value is greater than another
F012.4	Greater Than Equal To (≥)	ON (1) when the result of an unsigned comparison is less than or equal	Used to evaluate conditions where one value is less than or equal to another
F012.5	Not Equal (≠)	ON (1) when the result of an unsigned comparison is not equal	Used to evaluate conditions where one value is not equal to another

F012.0 – Less Than (<)

Description

The less than (<) flag is ON (1) when the result of a comparison indicates that the first value is less than the second value.

Use Case

Used to evaluate conditions in control logic where one value must be smaller than another.
Example: Check if the current temperature is below the set point.

F012.1 – Less Than Equal To (≤)

Description

The less than equal to (≤) flag is ON (1) when the result of a comparison indicates that the first value is less than or equal to the second value.

Use Case

Monitor conditions where a value must not exceed a threshold.
Example: Ensure the machine load is within safe operational limits.

F012.2 – Equal (=)

Description

The equal (=) flag is ON (1) when the result of a comparison indicates that the first value is equal to the second value.

Use Case

Verify equality between two variables or parameters.
Example: Check if the target and actual positions of a motor are the same.

F012.3 – Greater Than (>)

Description

The greater than (>) flag is ON (1) when the result of a comparison indicates that the first value is greater than the second value.

Use Case

Detect when one parameter exceeds another.
Example: Trigger an alert when the current exceeds a predefined limit.

F012.4 – Greater Than Equal To (≥)

Description

The greater than equal to (≥) flag is ON (1) when the result of a comparison indicates that the first value is greater than or equal to the second value.

Use Case

Monitor conditions requiring a minimum threshold.
Example: Ensure sufficient material is available before starting a process.

F012.5 – Not Equal (≠)

Description

The not equal (≠) flag is ON (1) when the result of a comparison indicates that the first value is not equal to the second value.

Use Case

Detect mismatches or unexpected values.
Example: Check if a safety condition is violated.

Status Relay Flags (F126)

The status flags, F126, indicate the state and configuration of system operations in the PLC.
These flags provide insights into program mode, redundancy, web server status, and I/O error handling.

Flag Bit	Name	Description	Use Case
F126.0	Program RUN Mode	ON (1) when PLC is in program RUN mode	Monitor and manage program execution states
F126.1	INITEND Bit	Indicates the completion of the initialization process when the INITEND instruction is executed	Used to trigger operations post-initialization
F126.2	Redundancy Status	Provides the status of redundancy in the PLC system	Monitor redundancy status for fault-tolerant systems
F126.3	Redundancy Configuration	Indicates the current redundancy configuration	Verify and manage system redundancy settings
F126.4	Web Server OS	Indicates if the PLC is using the web server operating system	Monitor and troubleshoot web server functionality
F126.5	I/O Error Process	Indicates the process for handling I/O errors	Diagnose and manage I/O error-handling mechanisms

F126.0 – Program RUN Mode

Description

The program RUN mode flag is ON (1) when the PLC is in program RUN mode.

Use Case

Monitor the operational state of the PLC.
Trigger alarms if the system is unexpectedly stopped.

F126.1 – INITEND Bit

Description

The INITEND bit flag is ON (1) when the PLC executes the INITEND instruction.

Use Case

Start operations only after the initialization phase is confirmed.
Ensure system readiness before execution.

F126.2 – Redundancy Status

Description

The redundancy status flag is ON (1) when redundancy system is active.

Use Case

Start operations only after the initialization phase is confirmed.
Ensure system readiness before execution.

F126.3 – Redundancy Configuration

Description

The redundancy configuration flag is ON (1) when redundancy configuration is set.

Use Case

Verify that redundancy configurations match the system’s requirements.
Diagnose issues related to redundancy mismatches.

F126.4 – Web Server OS

Description

The web server os flag is ON (1) when the PLC’s firmware is the web server operating system.

Use Case

Monitor web server availability for remote diagnostics or control.
Troubleshoot web server-related errors.

F126.5 – I/O Error Process

Description

The I/O process error flag is ON (1) if there are any errors while handling the I/O process.

Use Case

Diagnose and resolve I/O errors during operations.
Monitor fault-handling mechanisms to ensure minimal downtime.

Scan Time Relay Flags (F300 ~ F320)

The scan time relay flags, F300 ~ F320, display the minimum, current, and maximum scan time.
These flags can help diagnose the scan time of the PLC for a specific program.

The scan time relay flags, F300 ~ F320, are WORD data registers that can be accessed with the MOV instruction.

Flag	Minimum Scan Time (ms)
F300	Minimum Scan Time (ms)
F310	Current Scan Time (ms)
F320	Maximum Scan Time (ms)

Real-Time Clock Data Relay Flags (F400 ~ F430)

The real-time clock data relay flags, F400 ~ F430, display the year, month, date, day of the week, hour, minute, and second of the real-time clock.
These flags identify the real-time clock information of the PLC.

The real-time clock data relay flags, F400 ~ F430, are WORD data registers that can be accessed with the MOV instruction.

For more information about real-time clock data, refer to the DATERD instruction.

The month, date, day of the week, hour, and minute flags, F410 ~ F430, should be converted to with respect to 2’s complement.
- After converting the number to binary, convert each portion of the binary number back to decimal.

Conversion Examples:

Example 1: The flag F460 has the value 3,077.
- Converted to binary: 0000 1100 0000 0101
  - 1100 (upper WORD) converted to decimal: 12 (month)
  - 0101 (lower WORD) converted to decimal: 5 (day)
Example 2: The flag F470 has the value 1,025.
- Converted to binary: 0000 0100 0000 0001
  - 0100 (upper WORD) converted to decimal: 4 (day of the week: Thursday)
  - 0100 (lower WORD) converted to decimal: 1 (hour)
Example 3: The flag F480 has the value 1,288.
- Converted to binary: 0000 0101 0000 1000
  - 0101 (upper WORD) converted to decimal: 5 (minute)
  - 1000 (lower WORD) converted to decimal: 8 (second)

Flag	Item	Word
F400	Year
F410	Month	Upper
F410	Date	Lower
F420	Day of the week	Upper
F420	Hour	Lower
F430	Minute	Upper
F430	Second	Lower

Program Clock Data Relay Flags (F450 ~ F480)

The program clock data relay flags, F450 ~ F480, display the year, month, date, day of the week, hour, minute, and second from when the program execution begins.
These flags identify when the PLC began execution of the current program.

The program clock data relay flags, F460 ~ F480, are WORD data registers that can be accessed with the MOV instruction.

For more information about program clock data, refer to the DATERD instruction.

The month, date, day of the week, hour, and minute flags, F450 ~ F480, should be converted to binary with respect to 2’s complement.
- After converting the number to binary, convert each portion of the binary number back to decimal.

Conversion Example 1: The flag F460 has the value 3,077.
- Converted to binary: 0000 1100 0000 0101
  - 1100 (upper WORD) converted to decimal: 12 (month)
  - 0101 (lower WORD) converted to decimal: 5 (day)
Conversion Example 2: The flag F470 has the value 1,024.
- Converted to binary: 0000 0100 0000 0000
  - 0100 (upper WORD) converted to decimal: 4 (day of the week: Thursday)
Conversion Example 3: The flag F480 has the value 11,554.
- Converted to binary: 0010 1101 0010 0010
  - 0010 1101 (upper WORD) converted to decimal: 45 (minute)
  - 0010 0010 (lower WORD) converted to decimal: 34 (second)

Flag	Item	Word
F450	Year
F460	Month	Upper
F460	Date	Lower
F470	Day of the week	Upper
F470	Hour	Lower
F480	Minute	Upper
F480	Second	Lower

Clock Power Failure Relay Flags (F500 ~ F540)

The clock power failure relay flags, F500 ~ F540, display the count, year, month, date, day of the week, hour, minute, and second from when the power failure occurred.
These flags identify when the real-time clock experienced a power failure.

The clock power failure relay flags, F500 ~ F540, are WORD data registers that can be accessed with the MOV instruction.

For more information about clock power failure, refer to the DATERD instruction.

The month, date, day of the week, hour, and minute flags, F520 ~ F540, should be converted to binary.
- After converting the number to binary, convert it back to decimal.
Example: The flag F520 has the value 2,329.
- Converted to binary: 0000 1001 0001 1001
  - Converted to decimal: 9/25

The count flag, F500, records the number of power failures.

Flag	Item	Word
F500	Count
F510	Year
F520	Month	Upper
F520	Date	Lower
F530	Date of the week	Upper
F530	Hour	Lower
F540	Minute	Upper
F540	Second	Lower