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I/O Errors Relay Flags

I/O Error Relay Flags (F004)​

The I/O error flags, F004, indicate mismatches or errors in the PLC's input/output (I/O) modules.
These flags help diagnose configuration problems, hardware issues, or communication faults.

I/O Error Relay Flags
Flag BitNameDescriptionUse 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.