Specifications

SQ: 1-40
RS3: Service Quick Reference Guide
Troubleshooting
Serial (MPC) I/O Troubleshooting
Condition
Action
Analog Input No Reading
Inst. Low Alarm
AIB Field Reading -- 25%
1. Use a VOM to check that the input current is in the
range 4--20 mA. If a transfer card is installed,
measure between test points on the card.
Otherwise, measure at the marshaling panel by
breaking the loop.
If the current is OK:
Check the FlexTerm to ControlFile cables.
Replace the FIC.
Replace the Controller Processor Card.
If the current is not OK:
Check all fuses on the FIC.
2. Using the RMT 262 Field calibrator (or similar
device), input an appropriate current signal into the
marshaling panel.
If the value is wrong on the AIB screen,
replace the FIC.
If the v alue is correct on the AIB screen, check
the field wiring and the transmitter. Be sure to
check the system/self-powered jumper on the
FIC.
Analog Input shows
incorrect or unstable
reading.
1. Using the RMT 262 Field Calibrator (or similar
device), input an appropriate current signal into the
marshaling panel. Check the Field Reading on the
AIB screen.
If the reading is incorrect:
Calibrate the point.
Replace the FIC.
Replace the Controller Processor Card.
If the reading is correct:
Measure the transmitter c urrent with the RMT
262 (or similar device).
Check the field wiring for shorts and resistance
to ground.
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