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Diagnostics I/O Module Diagnostics and I/O Calibration
46 900 Control Station User Guide Revision 9
May 2014
Bad module details
When an I/O module’s error status is BAD MODULE, the module’s status LED on the controller is flashed
red with a number of quick strobes followed by a long off time. Table 23 outlines the potential module
diagnostics.
Table 23 Bad module details
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
Scanner Indicators in HC900
Process Controller manual, #51-52-
25-107).
If it’s flashing 6 times, proceed
with step 3.
If it’s flashing some other red
status code (refer to Scanner
Indicators in HC900 Process
Controller manual, #51-52-25-107)
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