Intelligent Technologies (IT.) D77A I/O Module Products
MN05002001E For more information visit: www.EatonElectrical.com 45
Troubleshooting and Maintenance

Status LED

The status LED is located on the upper left of the D77A I/O module as pictured in Figure 1,
Module Component Location. The LED’s status changes depending on the state of the I/O module.
Table 26: Status LED

Fault Codes

Table 27: Analog 10 Fault Codes
State LED Behavior
No Power OFF
Power-Up Routine OFF – CRC corrupt
Off-Line, OK (mostly off)
On-Line (mostly on)
Faulted (50%)
Identify device (burst)
Undiscovered
0 x 41 (65) Analog input over range.
0 x 42 (66) Analog input under range.
0 x 44 (68) Analog input open.
0 x 45 (69) Analog input shorted.