How to move some PLC Modbus data from WR21 Transport into Device Cloud data stream?

I have a WR21 Transport Router connected to a PLC via TCP/IP.

I can read the Modbus registers from my PC over cellular.

I need help getting this data to Device Cloud so I can store it there AND view it with a dashboard.

Can someone point me in the right direction?

You will want a Python application to upload the data. The Digi ESP application would be a good place to start:

http://www.digi.com/support/productdetail?pid=5499&type=drivers