Control panel wiring is something I've been thinking about recently.

My last retrofit, I used a Konnect wired to two DB25 breakout boards in the main control cabinet, wired everything on the control panel to another two DB25 BOBs, then used 25pin parallel cables to connect them.

For my next retrofit, I'm thinking about rationalising the number of switches by moving things like axis and step size selection to on screen buttons, so I can condense everything down to a single 25pin cable.


The other option is something using Modbus, however that's not something I would recommend unless you're reasonably competent at programming, and understand how Modbus works. It's also something I had pretty much dismissed for anything other than communicating with a PLC, however I've become aware of various Chinese Modbus IO modules on eBay recently, which could be a valid option. (just as an example, this type of module - https://www.ebay.co.uk/itm/Digital-I...N/392268000136 but there are also various relay output boards)