Rockwell Automation 1771-IFF/A,D17716.5.116 FAST ANALOG INPUT MODULE - Manual (Page 24)

2–8 Troubleshooting Your Input Module
Publication 1771Ć6.5.116 - July 1996
5. Attempt to equalize all grounds at the offending channel before
reconnecting the input wiring.
!
ATTENTION: Remove power from the 1771 I/O
chassis backplane and field wiring arm before
removing or installing input wiring.
•
Failure to remove power from the backplane or
wiring arm could cause module damage, degradation
of performance, or injury.
•
Failure to remove power from the backplane could
cause injury or equipment damage due to possible
unexpected operation.
6. If the common mode voltage cannot be removed on the input, an
isolation device may be required on that channel.
Disconnecting Inputs from the Field Wiring Arm One at a Time
While Observing Module Action
During this procedure, monitor the input data table of the
programmable controller and observe any changes which occur.
1. Make sure the field wiring arm is in position on the module.
2. Apply power to the 1771 I/O chassis.
3. While observing the input data table, remove one input at a time.
!
ATTENTION: Remove power from the 1771 I/O
chassis backplane and field wiring arm before
removing or installing input wiring.
•
Failure to remove power from the backplane or
wiring arm could cause module damage, degradation
of performance, or injury.
•
Failure to remove power from the backplane could
cause injury or equipment damage due to possible
unexpected operation.
4. When the offending input channel is disconnected, the input data
table will stabilize to some predictable values.