Honeywell HC900 Installation And User Manual page 186

Diagnostics and Troubleshooting - Scanner indicators
Number Possible Cause
of
Strobes
6 The Scanner cannot communicate
to a module or the module is
experiencing a diagnostic
condition.
6 An AI module's CJ temperature
reading is indicating a thermal
problem. The scanner determines
this problem not the AI module;
therefore, the module's status LED
will not indicate this diagnostic.
Possible reasons for this
diagnostic are:
1. One of the two CJs on the
module is indicating a
temperature reading greater
than 70 degrees C.
2. Both cold-junction sensors are
failing to convert.
3. The CJs are converting
properly, but their differential is
greater than 10 degrees C.
6 The scanner determined that a
module has a bad channel. In this
condition, the module's status LED
will not indicate the failure
because the Scanner determines
the condition, not the module itself.
7 One of the power-supplies failed.
174
Scanner Action
No action is taken.
No action is taken.
No action is taken
No action is taken
HC900 Process Controller Installation and User Guide
User Action
For each module with a red
blinking LED, follow the actions
described in the I/O Module
Diagnostic Indication, page 176.
1. Improve ventilation to rack
2. Replace AI module
Refer to the Bad I/O Channel
Diagnostics on page 177 to
determine the nature of the
problem and possible user
actions.
Replace the power-supply
Revision 19
06/14