
Self-diagnostics functions are incorporated into the controller. The table on the following page
shows the alarm codes that are displayed as a result of self-diagnostics:
■
Self-diagnostics at power ON
●
●
PROM error
An error in the system program stored to PROM has been detected.
However, note that not all PROM errors are detected. Some errors
are detected as controller operation errors.
The corresponding alarm code is displayed when this error is
detected.
●
●
Adjustment value error
An error in the analog I/O adjustment data stored to volatile memo-
ry has been detected.
The corresponding alarm code is displayed when this error is
detected.
●
●
RAM backup error
An error in the RAM backup function has been detected.
When this error is detected, a general reset is carried out.
An alarm code is not displayed for this error.
●
●
Board configuration error
An error in the board configuration (combination of different PCBs)
has been detected according to the catalog No. of the controller.
The corresponding alarm code is displayed when this error is
detected.
■
Self-diagnostics at each sampling cycle
●
●
Analog input error
A probable cause of this error is a disconnected analog input. This
error is detected when the analog input is outside the -10.0 to 110.0%
range.
The corresponding alarm code is displayed when this error is
detected.
●
●
MFB (motor feedback) input error
Disconnected MFB input or a short-circuit has been detected on 2G
output models.
The corresponding alarm code is displayed when this error is
detected.
9-2
Chapter 9. MAINTENANCE & TROUBLESHOOTING
9 - 2
Self-diagnostics and Alarm Code Display