Manual

Troubleshooting
Chapter 7
72
Figure 7.1
Module
Indicators for Chassis A or B
12292
ACTIVE
(green)
CBM
FAULT
(red)
I/O RACK
FAULT
(red)
Output status
indicators are red.
On = output
Blown fuse
indicators are clear.
On = blown fuse
Input Module Indicators
Input status indicators are clear. On = input
One indicator per terminal.
1771-PM Module 1771-IA Modules
1771-OD Module
Refer to tables 7.A and 7.B
Output Module Indicators
PM Module Indicators
Table 7.A
ACTIVE Indicator
If the ACTIVE indicator is blinking, identify the problem by the number of blinks. There are 2 sets of blinks:
first set of blinks short pause second set of blinks long pause
repeat continuously
Number of Blinks
1st Set 2nd Set
Problem Correction
1 3 Faulty RAM Replace 1771PM module
1 4 Faulty PROM Replace 1771PM module
2 1 Illegal rack address Set the 1771PM module switches as detailed in chapter 3
2 3 The 1771PM modules contain dif ferent firmware Install 1771PM modules with identical revision codes
3 2 Missing a 1771PM module at power up Install and fully seat both 1771PM modules
3 4 Illegal interrupt Cycle power Replace 1771PM module
4 1 Firmware fault Replace 1771PM module
4 3 Lost communications between 1771PM modules,
or watchdog timed out
Check connections between 1771PM modules or
Replace 1771PM module