Diagnostics and Troubleshooting - User Interface
Revision 5 HC900 Hybrid Controller Installation and User Guide 133
9/03
I/O Module Diagnostics
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. The table below outlines the potential module diagnostics.
Table 28 - Bad Module Diagnostics
DI DO Failure Description AI
O
on-
act
AC DC Re-
lay
AC DC
# of
Strobes
User Action
FAIL SAFE The module is in the
failsafe state because
it is not receiving
message requests
from the main
CPU/Scanner at a
rate equal to the
value configured for
its failsafe timeout.
√ √ √ √ √ √ √ √
1 1. If expansion rack(C50 CPU only), check
communication link connection to main CPU
2. Remove the module and check for a bent
pin, then reinsert the module.
3. Measure Power Supply voltage; if not within
specifications, replace the power supply.
4. Replace the I/O Module.
5. Remove other modules and replace one at a
time until the problem reoccurs. Most likely
the last module inserted needs to be
replaced.
6. Replace the rack.
EAROM EA ROM Failed its
checksum
√ √
2 Replace Module
RAM
√ √
3 Replace Module
ROM 4
+24 V
√ √ √
√
5 1. Remove the module and check for a bent
pin, then reinsert the module.
2. Replace module.
3. Measure 24V at test points on Power Supply.
If below 21.6V, replace Power Supply.
4. Replace Rack.
FACTORY CAL CRC failure of
primary and backup
factory calibration
√
6 Replace Module.
FIELD CAL CRC failure of field
calibration values
√ √
7 None; controller will switch card to Factory Cal.
HARDWARE General Hardware
Failure (AI=convertor
not working)
√
8 Replace module.
HW/SW Key The software residing
on the module does
not match the module
type. This diagnostic
should only result in
the factory.
√ √ √ √ √ √
9 Replace module.
Shift Register The loopback test of
the shift register
failed.
√ √ √ √ √ √
11 Replace module.
