Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual User Manual
Page 78

7–2
Troubleshooting
Publication 1771ĆUM127B-EN-P - December 2002
Table 7.A shows indications, probable causes and recommended
actions to correct common faults which may occur.
Table 7.A
Troubleshooting Chart
Indication
Probable Cause
Recommended Action
Both indicators are OFF
No power to module
Check power to I/O chassis.
Recycle as necessary.
Both indicators are OFF
Possible short on the module
LED driver failure
Microprocessor, oscillator or EPROM failure
RUN/FLT indicator ON red
If immediately after power-up, indicates RAM or
EPROM failure.
Replace module.
RUN/FLT indicator ON red
If duringoperation, indicates possible
microprocessor or backplane interface failure.
Internal fuse bad
RUN/FLT indicator is
flashinggreen
Power-up diagnostics successfully completed.
Normal operation.
RUN/FLT indicator is solid green
Initial block transfer write successfully completed
CAL/COM indicator is green
(solid or flashing)
Normal operation
None required
CAL/COM indicator is green and
RUN/FLT indicator is green but
module data is wrong(for
example, with cable off, input
channel data values are at
minimum scale values)
Internal module problem
Replace module
Design your program to monitor module and channel status bits, 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 module
conditions as shown in Table 7.B.
The module sets a bit (1) to indicate it has detected one or more of
the following input channel conditions (Table 7.D), or output channel
conditions (Table 7.C).
Troubleshooting with
the Indicators
Status Reported by
the Module