Just took a look at your drive manual, and it's... really sparse.
I don't know of anything in lcec or cia402 that constantly polls the drive(s) for communication status, but I had an idea that might be worth exploring...
What I was thinking is to use one of the drive's digital outputs as a tattle-tale. It's not clear in the manual if the DOs reset on loss of communication, but on my Stepperonline A6's that's an option only found in the tuning software.
I can program my drives' digital outputs to either retain the last state or turn off if communication is lost.
If you can set yours to turn off, then you could create DO hal pins in xml file. Those pins are then turned on in HAL whenever LCNC is running. The DO is then connected to an LCNC input - a DI on a different drive or other Ethercat slave device. That input is connected to motion.external-fault-NN - and it all acts like a drive communication estop.
If the drive is unplugged, the DO turns off... then input then turns off, which triggers an external fault in LCNC.
It all depends if you can set the outputs to non-latching in the drive tuning software and you have a spare input somewhere.
Reminds me I need to test my own system for an Ethercat cable failure.
