Honeywell DCP552 Mark II - Manual (Page 172)

Chapter 10. TROUBLESHOOTING
10 - 1 Self-Diagnostic Functions and Alarm Code Displays
10-1
The DCP552 is equipped with the self-diagnostic functions described below. Alarm codes and the result of self-
diagnostics are listed on the following pages.
■ Power ON self-diagnostic routines
● RAM backup failures
This routine is designed to detect errors in the RAM backup function. When a
failure is detected, a general reset is performed. No alarm code is displayed.
● Board configuration failures
This routine detects failures caused when boards (circuit boards) not designed to
be used with the DCP552 . Alarm codes are displayed when errors are detected.
■ Self-diagnostic routines performed each sampling cycle
● Analog input failures
Failures are detected when the analog input signal due to disconnection or other
cause lies outside the –10.0 to +110.0% range.
Alarm codes are displayed when errors are detected.
■ Self-diagnostic routines performed continuously during operation
● PROM failures
This routine is designed to detect errors in system programs stored in the PROM.
Not totally infallible, there are cases where errors go undetected and result in
measuring device operation failure.
Alarm codes are displayed when errors are detected.
● Adjustment data failures
This routine detects errors in analog inputs and output adjustment data stored in
non-volatile memory. Alarm codes are displayed when errors are detected.
● Program failures
This routine detects failures in program setting data stored in a backup RAM.
Alarm codes are displayed when errors are detected.
● Parameter failures
This routine detects failures in parameters stored in a backup RAM. Alarm codes
are displayed when errors are detected.
● Low battery voltage
This routine detects low voltage conditions in the battery that backups RAM data.
The BAT LED on the console goes on when battery voltage is too low.