Chapter 3 General Specifications
3 – 49
Err.
code
Error name
[Detected when]
Description PLC
system
Applica-
tion
ERR
LED
20
Misalignment /
Illegal instruction /
Privileged instruction
[Always]
Microprocessor has detected an exception
processing in application.
Run
Stop
21
Retain identity mismatch
[Power on]
Retain data memory is undefined status due to
battery empty.
Read the next page for further information
Run
Stop
23 Unresolved
external
references
[Always]
Unresolved external references are detected.
Run
Stop
24 Software
watchdog
of
IEC task expired
[Always]
Actual cycle time has exceeded watchdog time.
Set longer watchdog time.
Run
Stop
25 Processor
load
watchdog
[Always]
Microprocessor load watchdog of all IEC task
has been exceeded.
Set longer interval time of task.
Run
Stop
26
IEC task configuration
failed
[Always]
IEC task configuration has failed.
Run
Stop
27
Division by zero
The divisor of division command is 0 in IEC
program.
Run
Stop
31
Load boot project failed
[Power on]
Checksum value of application (user program)
in FLASH does not match the checksum
calculated.
Run
Stop
70
I/O configuration error
[Always]
I/O configuration does not match with actual I/O
modules.
Run Run
71 Battery
error
[Always]
Battery voltage is low or battery is disconnected.
Run Run
Blink
72
Special module failure
[Always]
Hardware error is detected in special module or
communication module.
Run Run
74
Comm. module
configuration error
[Download]
Configuration error is detected in
communication module.
Run Run
77
FLASH writing failure
[FLASH writing]
Failure has been detected in writing FLASH
memory or the number of writing times has been
exceeded.
Run Run
78
Parameters in FLASH
check sum error
[Power on]
Checksum value of parameters in FLASH (IP
address, etc.) does not match the checksum
calculated.
Run Run
: ON, : Blink, : OFF
CAUTION
If error cause is removed, error code remains except for error code 71 (battery error).
71 Error and ERR LED blinking automatically disappear if battery is replaced to new one.