Honeywell 900 User Manual page 57

I/O Module Diagnostics and I/O Calibration
Status Possible Cause
MISSING/NO
Main CPU is unable
COMM
to communicate to
the module for one of
the following reasons:
1. Module is not
installed
2. The module cannot
communicate with the
controller CPU or the
expansion rack CPU
because of a
backplane problem.
3. Module is on an
expansion rack and
the expansion rack
communications is
failing
Module is reporting a
BAD MODULE
diagnostic condition.
See Table 23 .
BAD See Table 24
CHANNEL
Revision 9
May 2014
Controller Action
See MISMATCH.
See MISMATCH.
1. Associated block sets its fail pin on, its
warn pin off, and its output pin to the
failsafe value.
2. Associated block sets its IO status as
denoted in Table 24.
3. Associated rack monitor block's module
fail pin is turned on.
4. Associated rack monitor block's RACK
OK pin is turned off.
5. SYSTEM MONITOR block's HW OK
pin is turned off.
900 Control Station User Guide
Diagnostics
What to do
Action is based on the RACK STATUS
indication. If RACK STATUS is not
MODULE ERROR, then follow the
prescribed action defined for the RACK
STATUS diagnostic.
For MODULE ERROR, do the following:
1. Verify configuration
2. Install module.
User should inspect the module's status
LED to determine the nature of the
problem. Table 23 describes the user
action for the various LED diagnostics.
See Table 24
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