communication with a atlas copco combox-s

We are trying to communicate and establish the network since commissioning of the plant. Since then we are unable to connect. we tried all sorts of experiments on it. They simply completed logic part not able to communicate. On number of trials we saw that in dcs that the slave is not responding. Recently in i/o module we have tx and rx are blinking and not previously. So we want to know with this tx and rx. Can we go further to check the fault? I/O module is CI 853 to (Rs 232 to Rs 485 ICP CON converter) to atlas copco combox-s to Elektronikon MkIV compressor controller. Kindly suggest.

Assuming Atlas Copco makes functional products, it can work somehow.

However, my experience with large compressors is they use 3-phase power and you can have serious grounding problems. So make sure you have a signal-reference wire between the compressor and your RS-232/485 converter - so use 3 wires, not 2 (or 5 instead of 4).

Hopefully, your RS-232/485 converter is also optically isolated or a compressor fault might burn your RS-232 device.