Failure of the Discrete Links

TASK 31-32-00-810-932-A
Failure of the Discrete Links

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
Discrete Links Failure

3. Fault Confirmation
Subtask 31-32-00-710-058-A

A. Not applicable, refer to the initial procedure .

4. Fault Isolation
Subtask 31-32-00-810-183-A

A. Trouble Shooting Procedure for the Discrete Links.

Use the procedure that follows to find:

if the fault is in one of the receivers (computer B, C or D) of the discrete signal (refer to the schematic in the initial procedure to find the receivers related to the discrete signal), or
if the fault is an unwanted ground of the discrete signal.

A fault in one receiver can change the status of the discrete signal and cause a fault detection by all the receivers.

The initial trouble shooting procedure can only let you know that the possible cause of the fault is the discrete source A or the wiring (discontinuity of the discrete signal).
(1) Remove the computer B.

(2) Do the test given in Para. 3. of the initial procedure.

(a) if the fault stops:

replace the computer B.

(b) If the fault continues:

install the computer B
remove the computer C
do the test given in Para. 3. of the initial procedure.

1 If the fault stops:

replace the computer C.

2 If the fault continues:

install the computer C
remove the computer D
do the test given in Para. 3. of the initial procedure.

a If the fault stops:

replace the computer D.

b If the fault continues:

remove the computers B, C, D and the discrete source A
do a check of the wiring for a short to ground
install the computers B, C, D and the discrete source A.

c If the fault continues:

continue the initial procedure.

[Rev.8 from Aug 2018] 2026.04.04 04:29:58 UTC