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

Appendix 4
The following table shows how to read the list of special relays (SM).
Item
No.
Name
Content
Details
Set by (when to set)
Do not change the special relays which are to be set by the system by performing operations such as program
execution and device test. Doing so may result in system down or disconnection of communication.
Diagnostics information
The special relays for diagnostics information are as follows.
No. Name
SM0 Latest diagnostics error
SM1 Latest self-diagnostics error
SM53 AC/DC DOWN
SM60 Fuse Blown
SM61 I/O module verify error
SM80 Detailed information 1 in-
use flag
SM112 Detailed information 2 in-
use flag
Special Relay List
Description
The number of the special relay is indicated.
The name of the special relay is indicated.
The content of the special relay is indicated.
The details of the special relay is indicated.
The timing to set each device by system and/or user is indicated.
(Set by)
• S: Set by a system
• U: Set by a user (by a program, engineering tool, GOT, or test function from an external device).
• U/S: Set by both a user and system.
(When to set)
• Error occurrence: Set when an error occurs.
• Status change: Set only when the status is changed.
Description Details
OFF: No error This relay turns ON when the diagnostics error occurs.
ON: Error The ON state is retained even after the error is cleared
later.
OFF: No error This relay turns ON when the self-diagnostics error
ON: Error occurs. The ON state is retained even after the error is
cleared later.
OFF: AC/DC DOWN not • This relay turns ON when a momentary power failure
detected within 20 ms is detected while the AC power supply
ON: AC/DC DOWN module is in use. This relay is reset after the power is
detected turned OFF and ON.
• This relay turns ON when a momentary power failure
within 10 ms is detected while the DC power supply
module is in use. This relay is reset after the power is
turned OFF and ON.
OFF: Normal • This relay turns ON when at least one output module is
ON: Module with blown in fuse blown state. The ON state is retained even after
fuse the error is cleared later.
• The fuse blown state check is also performed for output
modules on the remote I/O station.
OFF: Normal • This relay turns ON when the state of the I/O module is
ON: Error different from the one registered during power ON. The
ON state is retained even after the error is cleared later.
• I/O module verification is also performed for modules
on the remote I/O station.
OFF: Not used This relay turns ON if the detailed information 1 exists
ON: In use when SM0 turns ON.
OFF: Not used This relay turns ON if the detailed information 2 exists
ON: In use when SM0 turns ON.
Set by (when to set)
S (error occurrence)
S (error occurrence)
S (error occurrence)
S (error occurrence)
S (error occurrence)
S (status change)
S (status change)
APPX

Appendix 4 Special Relay List

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