Connecting to Weatherford 8500 in linux

For pulling data from Weatherford 8500 RPC, I see that Kepserver/TOP server is used as OPC-UA server with drivers supporting 8500 serial protocol and ignition as OPC-UA client. However Kepserver/TOP server can run only in windows. We have an edge box running linux and we are planning to run ignition edge on it. Is there a way to pull data from Weatherford 8500 in linux into ignition?

This page indicates they support Modbus RTU and TCP in addition to the 8500 protocol.

Is this an option for you?

Yes, this is an option, but I did not find the register to metric mapping spec, I pinged Weatherford guys waiting for response. If someone already have one, do you mind sharing?
Also the brochure says It can also communicate via Modbus RTU protocols, for data gathering and retrieval of surface dynamometer cards.
With Modbus looks like you can only gather data not send instructions to the RPC, I am stuck here.