XR Expansion Port pinout on High-Power Relay Controller 16-Channel Board


We have a High-Power Relay Controller 16-Channel (ZUXPR1630PROXR_ETHERNET) board that is no longer communicating to a 8-Channel (XR830) expansion board. The 16 Channel boards relay’s operate, but the expansion boards relays stopped working. There is power. We checked the ribbon cable for continuity and it is plugged into the correct port.

Is there a pin-out I can check on the XR expansion port to try an isolate whether the problem is in the main board or expansion board?



A communication failure typically indicates the TPIC6B595 chip needs to be replaced, you can usually swap chips between boards for testing. These chips are available from DigiKey.com. Also, we have a long 5-year warranty. If you send them in, we will complete a full diagnostic and replace any components that may be damaged. We do not have a pin-out available.


I would guess this chip controlling the relays? One for every 8 relays, that would explain why there is 2 on the 16 channel board and one on the 8 channel extension.


That’s correct, each chip controls 8 relays. Data passes from the main CPU through each of the chips. If any of the chips in the chain fail, it will stop the flow of data. Sometimes Bank 1 relays will work, Bank 2 will not, and the root cause would be the Bank 1 chip. While it may appear to work, it may not pass data to Bank 2. So the fix would be to replace the Bank 1 chip, even though Bank 2 relays appear to fail. Hope this helps.


This is very helpful. One last question to expand on that. So does that mean that if the chip in Bank 2 fails, the relays in bank 2 may still work but now that stops the chain to the expansion board? So it appears that the expansion board is bad but in reality its the ic chip in bank 2 of the main board that failed?

Thanks again,


Exactly Mike. Put simply, if a problem shows itself on Bank 3, the Bank 2 or Bank 3 chip may be damaged. In some cases, they could both be damaged.
Hope this helps.