Honeywell HC900 - Table 31 - I;O Module LED Diagnostics

Diagnostics and Troubleshooting - I/O Module Indicators
176 HC900 Process Controller Installation and User Guide Revision 19
06/14
I/O Module Diagnostic Indication
To indicate the type of diagnostic failure, the module’s status LED is flashed red with a number of quick
strobes followed by a long off time. Table 31 outlines the potential module diagnostics.
Table 31 – I/O Module LED Diagnostics
Number of
Strobes
Failure Description AI AO DI DO PFQ User Action
Contact AC DC Relay AC DC
1 FAIL SAFE The module is in the failsafe state
because it is not receiving message
requests from the CPU or Scanner
at a rate that satisfies the configured
failsafe timeout.
√ √ √ √ √ √ √ √ √
1. If expansion I/O rack, go to step 2
.
If no expansion I/O rack, go to
step 3.
2. Check the Scanner status LED
(see p. 171).
If it’s flashing 6 times, proceed
with step 3.
If it’s flashing some other red
status code, refer to
Table 29
to solve that problem first.
If it’s flashing green, the module
probably is not required in the
configuration.
If it’s not on or steady, cycle
power to the scanner.
3. Make sure the module is the
correct one for the configuration.
4. Remove the module and check
for a bent pin, then reinsert the
module
5. Replace the module
6. Remove other modules and
replace one at a time until the
problem reoccurs. Most likely the
last module inserted needs to be
replaced.
7. Replace the rack.
2 EAROM EA ROM Failed its checksum
√ √
1. Remove/reinsert module.
2. Replace module.
3 RAM
√ √ √ √ √ √ √ √ √
4 ROM
√ √ √ √ √ √ √
5 +24 V
√ √ √ √
1. Remove the module and check
for a bent pin, then reinsert the
module
2. Measure power supply voltage. If
not correct, replace power supply.
3. Replace module
4. Replace rack
6 FACTORY CAL CRC failure of primary and backup
factory calibration
√ √
Replace module.
7 FIELD CAL CRC failure of field calibration
values
√ √
1. Remove/reinsert module.
2. Replace module.
8 HARDWARE General Hardware Failure
(AI=convertor not working)
√
Replace module.
9 HW/SW Key The software residing on the
module does not match the module
type. This diagnostic should only
result in the factory.
√ √ √ √ √
Replace module
11 Shift Register The loopback test of the shift
register failed.
√ √ √ √ √ √
Replace module