Pellerin Milnor Corporation 73
The following information may also be useful to determine the position of an output or input on
an I/O board from its label on the Diagnostics display:
• The digital inputs are labelled 0–63.
– Digital inputs 0–15 correspond to inputs 0–15 on 8/16 Board 1
– Digital inputs 16–31 correspond to inputs 0–15 on 8/16 Board 2
– Digital inputs 32–47 correspond to inputs 0–15 on 8/16 Board 3 (WTB only)
– Digital inputs 48–63 correspond to inputs 0–15 on 8/16 Board 4 (WTB only)
• The digital outputs are labelled 0–127.
– Digital outputs 0–7 correspond to outputs 0–7 on 8/16 Board 1
– Digital outputs 8–31 correspond to outputs 0–23 on 24 Output Board 1
– Digital outputs 32–39 correspond to outputs 0–7 on 8/16 Board 2
– Digital outputs 40–63 correspond to outputs 0–23 on 24 Output Board 2
– Digital outputs 64–71 correspond to outputs 0–7 on 8/16 Board 3 (WTB only)
– Digital outputs 72–95 correspond to outputs 0–23 on 24 Output Board 3 (WTB only, cur-
rently unused)
– Digital outputs 96–103 correspond to outputs 0–7 on 8/16 Board 4 (WTB only)
– Digital outputs 104–127 correspond to outputs 0–23 on 24 Output Board 4 (WTB only)
4.8.3 About the Yellow Light and Serial Communication
BNCLWT01.C12 0000217354 E.2 A.3 B.3 1/2/20 1:22 PM Released
Figure 41. Serial Link Light
Each board has a yellow serial link light, as shown in
Figure 41, page 73.
This light tells much about the status of serial communi-
cation and the related hardware. Consider three possible
conditions:
1. the light blinks
2. the light remains off
3. the light is steady on
blinks serial data is passing between this board and its central processor. This board is function-
al. However, this condition says nothing about the quality of the serial data. It does not ensure
that the data is uncorrupted by, for example, electromagnetic interference (EMI).
steady off the board has lost serial communication with the processor. If the machine contains
at least two boards of this type, make a note of the board addresses, as set on the rotary
switches on the boards. Then swap the boards and give each board the address of the board it
replaces. If the light that was not blinking is still not blinking (if the problem moved with the
board), the board is dysfunctional. If the light on the board that now occupies the problem po-
sition is not blinking, it is likely that there is an open in the serial link wiring.
steady on this board is dysfunctional and the board is interfering with serial communication
throughout the serial link. Replace the board.
Troubleshooting
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