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Module Errors Relay Flags

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.

Error Relay Flags
Flag BitNameDescriptionUse Case
F003.0Error (Major Error)ON (1) during any error conditionUsed to monitor the system for active errors
F003.1Warning (Minor Error)ON (1) during warning conditionsUsed to identify non-critical error warnings
F003.2Watchdog Timer ErrorON (1) when a watchdog timer error occursUsed to handle program execution timeout errors
F003.3I/O ErrorON (1) during I/O combined errorsHelps detect hardware or communication issues
F003.4Battery LowON (1) when the battery voltage is below the thresholdUsed to prompt battery replacement
F003.5Forced ON/OFFON (1) when forced ON/OFF is applied to I/O pointsMonitors 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.

F3.0 OFF​

F3.0 ON​

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.

F3.1 OFF​

F3.1 ON​

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.

F3.2 OFF​

F3.2 ON​

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.

F3.3 OFF​

F3.3 ON​

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.

F3.4 OFF​

F3.4 ON​

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.

F3.5 OFF​

F3.5 ON​