Honeywell HC900 - Replacing the Controller Module

Revision 6 HC900 Process & Safety Controller User and Installation Manual 185
21 April 2017
Number
of
Strobes
Possible Cause
Scanner Action
User Action
5
C75 only. The communications
with the reserve is failing for the
following reasons:
1. There is a problem with the
connection between the
scanner and the reserve.
2. The scanner port used to
communicate to the reserve
has a hardware failure
C75 only. This problem may cause on-
demand failover attempts to be unsuccessful.
C75 only:
1. Verify that the CPU A cable is
connected to the A port, and
the CPU B cable is connected
to the B port on the Scanner
2.
2. If a switch is used, check that
all cables are properly
connected to the switch,
proper crossover cables are
used, that the switch is
powered, and it supports 100
Base-T.
3. Check cable shielding for
proper grounding and noise
immunity.
4. Make sure the cables have
the correct pinout.
5. Cycle power to the Scanner 2.
6. Cycle power to the switch.
7. Cycle power to the reserve.
8. Replace the expansion rack’s
scanner module.
9. Ensure that the Scanner 2 and
reserve software versions are
compatible. If not, perform a
firmware upgrade.
10. Replace the expansion rack’s
power supply.
11. Replace the expansion rack.
12. Replace the main CPU.
6
The modules installed do not
agree with those required by the
configuration.
No action is taken.
Verify that the correct modules
are installed for the configuration.
6
The Scanner cannot communicate
to a module or the module is
experiencing a diagnostic
condition.
No action is taken.
For each module with a red
blinking LED, follow the actions
described in the I/O Module
Diagnostic Indication, page 188.
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.
No action is taken.
1. Improve ventilation to rack
2. Replace AI module