Appendix 4 List Of Special Relay Areas - Mitsubishi Electric MELSEC iQ-R Series User Manual

Appendix 4
The following table lists items in the list.
Item
No.
Name
Data stored
Details
Set by (setting timing)
Do not change the data set by the system in a program or by a device test. Doing so may result in system
down or communication failure.
List of Special Relay Areas
Description
Special relay number
Special relay name
Data stored in the special relay and its meaning
Detailed description of the data stored
Set side of data (system or user) and timing when data is set by the system
<Set by>
• S: System
• U: User (program, engineering tool, GOT, or other testing operations from external device)
• U/S: User and system
<Set timing>
• Every END: Data is set every time END processing is performed.
• Initial: Data is set when initial processing is performed (e.g. powering on the system, changing the operating status from
STOP to RUN).
• Status change: Data is set when the status is changed.
• Error: Data is set when an error occurs.
• Instruction execution: Data is set when an instruction is executed.
• Request: Data is set when requested by a user (using the special relay).
• Writing: Data is set when a user performs a writing operation.
• During END: Data is set when END processing is performed.
• Power-on to RUN or STOP to RUN: Data is set when the operating status changes from power-on to RUN or from
STOP to RUN.
• System switching: Data is set when two systems are switched (between the control system and the standby system)

Appendix 4 List of Special Relay Areas

A
APPX
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