Metso Automation MAX Controls
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277573
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Chapter 8
Alarms and Diagnostics
Annunciation of Alarms
Diagnostic alarms originating at a DPU are posted as remote alarms on the
maxSTATION Alarm List. Refer to Publication 277558,
Alarm Message
Reference Guide
, for a description of these alarms. DPU front panel LEDs
also indicate certain fatal diagnostic alarms.
Front Panel Numeric LEDs
During normal operation, the numeric LEDs reflect the activity of the
DPU
Bus
Card). If a DPU is reset, it initially displays 88; during its restart cycle, it
displays FF, progresses through a series of steps counting down from 0F to
06, then goes online. Once online, a healthy DPU typically displays a rapidly
flickering number whose value is predominantly 07. If a DPU is
disconnected from the data
DPU Bus
, it displays a steady value of 07.
If a DPU has a failure which prevents the
DPU Bus
Card from working
properly, the DPU will drop off the data
DPU Bus
. Front panel LEDs will
then be used to display two diagnostic codes alternating every 1.5 seconds,
one reflecting the condition detected by the
DPU Bus
Card, and the other
reflecting the highest priority alarm reported by any of the processors. The
DPU Bus
Card reports the following detected conditions:
DA
The
DPU Bus
address set on the front-panel rotary switches is
illegal (e.g., 00).
DC
Jabberhalt timeout; the
DPU Bus
Card transmitted on the
DPU Bus
too long.
DF
The
DPU Bus
Card either detected a stack imbalance or executed
an illegal instruction.
The alarm code alternating with one of the above
DPU Bus
Card codes may
be any of the alarm codes listed in the
Alarm Message Reference Guide
. In
most cases, the two codes are independent; in a few special cases, one may
be the cause of the other. The most likely of those special cases is DC
(jabberhalt) combined with one of the following:
