Filter
Top Products
9
EMC AND LOW
VOLTAGE
DIRECTIVES
10
LOADING AND
INSTALLATION
11
MAINTENANCE AND
INSPECTION
12
TROUBLESHOOTING APPENDICES INDEX
12
TROUBLESHOOTING
12.6 Special Relay List
12 - 78
(1) Diagnostic Information
Table12.12 Descriptions of the special relay headings
Number Name Meaning Explanation
Set by
(When Set)
Corresponding
CPU
SM0
Diagnostic
errors
OFF : No error
ON : Error
• Turns ON when an error is detected by
diagnostics
(Includes when an annunciator is ON)
• Remains ON if the condition is restored to
normal thereafter.
S (Error)
QS
SM1
Self-diagnosis
error
OFF : No self-diagnosis
errors
ON : Self-diagnosis
• Turns ON when an error is detected by self-
diagnostics
(Does not include when an annunciator is
ON)
• Remains ON if the condition is restored to
normal thereafter.
S (Error)
SM5
Error common
information
OFF : No error common
information
ON : Error common
information
• When SM0 is ON, ON if there is error
common information
S (Error)
SM16
Error individual
information
OFF : No error individual
information
ON : Error individual
information
• When SM0 is ON, ON if there is error
individual information
S (Error)
SM50
Error reset OFF ON: Error reset • Conducts error reset operation U
SM51
Battery low
latch
OFF : Normal
ON : Battery low
• ON if battery voltage at CPU module or
memory card drops below rated value.
• Remains ON if the battery voltage returns to
normal thereafter.
• Synchronous with BAT. LED
S (Error)
SM52 Battery low
OFF : Normal
ON : Battery low
• Same as SM51, but goes OFF subsequently
when battery voltage returns to normal.
S (Error)
SM53
AC DOWN
detection
OFF : AC DOWN not
detected
ON : AC DOWN
detected
• Turns ON if an instantaneous power failure of
within 20ms occurs during use of the AC
power supply module.
Reset when the power supply is switched
OFF, then ON.
S (Error)
SM56 Operation error
OFF : Normal
ON : Operation error
• ON when operation error is generated
• Remains ON if the condition is restored to
normal thereafter.
S (Error)
SM61
I/O module
verify error
OFF : Normal
ON : Error
• Turns ON if the I/O module differs from the
status registered at power on.
• Remains ON if the condition is restored to
normal thereafter.
S (Error)
SM62
Annunciator
detection
OFF : Not detected
ON : Detected
• Goes ON if even one annunciator F goes ON.
S (Instruction
execution)