Troubleshooting 753-478 AI module error on install

CODESYS
1

If anyone has any ideas on troubleshooting this 753-478, I would greatly appreciate it.

I just installed my 753-478 AI module (not new but new to me) to my 750-8212 PLC base module. The LED lights on the 478 blink only for a second during PLC start-up, then go dark. The base module never lights up the I/O light. SYS and RUN green, nothing red. When using WAGO I/O check, the error below is returned. The CODESYS IDE cannot link up with this present. As soon as I remove this module, everything works again. 24V is being relayed into the module (as measured on the terminal 2)

I/O check error:
2025-01-11, 14:30:48 - Read node configuration …
2025-01-11, 14:30:59 - Node configuration not read!
# Communication with head station failed! (Error Code: 0x3000274C)

Thank you.

2

Does this occur with wiring connected to the 753-478, or with no wires attached at all? If it is the former, there is possibly a wiring issue and I would try again with no wires preset. If it is the latter…

(a) First add up to the total internal 5V power required by all modules (reference each module’s data sheet). If this analog module is the last one in the chain, perhaps it has pushed you just over the 2000 mA supply and you will need to add a 750-613 midway through the system to refresh the internal power supply.
(b) If it isn’t (a), then you likely have a damaged 753-478 on hand.

1 Like
3

Thank you, Adam. There are no wires yet attached. I will review the possibility of over use of power supply, but feel likely the board is bad.