Rockwell Automation 1771-IL/B , D17716.5.91 ISOLATED ANALOG INPUT Module - Manual (Page 47)

RUN
FLT
RUN
FLT
RUN
FLT
RUN
FLT
Troubleshooting
Chapter 7
7-2
Table 7.A shows indications, probable causes and recommended actions to
correct common faults.
Table 7.A
Troubleshooting Chart for the Isolated Analog Input Module (1771-IL series B)
Indication Probable Cause Recommended Action
B T
No power to module
Check power to I/O chassis. Recycle as
necessary.
Both RUN and FLT are OFF
Possible short on the module
LED driver failure
.
Red FLT indicator ON and
Green RUN indicator is ON
Microprocessor, oscillator or EPROM failure
Replace module.
If immediately after power-up, indicates RAM or
EPROM failure.
1
Red FLT indicator ON If during operation, indicates possible
microprocessor or backplane interface failure.
1
Replace module.
Hardware failure (blown fuse, etc.)
Powerup diagnostics successfully completed. Normal operation.
Green RUN indicator is
flashing
If indicator continues to flash, and write block
transfers (BTW) cannot be accomplished, you
have a possible interface failure.
Replace module.
1 When red LED is on, the watchdog timer has timed out and backplane communications are terminated. Your user program should monitor communication.
Status Reported in Word 1
Design your program to monitor status bits in the lower byte of word 1, and to
take appropriate action depending on your application requirements. You may
also want to monitor these bits while troubleshooting with your industrial
terminal. The module sets a bit (1) to indicate it has detected one or more of the
following conditions as shown in Table 7.B.
Troubleshooting with the
Indicators
Status Reported by the
Module