I have several devices communicating using Modbus protocol and I have sucessfully communicated with them except for one that communicates with the Remote Procedure Call (RPC) protocol and it said that the data format is JSON.
How can I communicate with RPC through rapidscada?
Here also I attach the link to the datasheet/manual. http://files.sma.de/dl/2585/SWebBoxRPC-BA-en-14.pdf
OPC server is a software developed by a manufacturer of controller.
First, you should download, install it and get data from a device.
If you need support in this process, you should ask developers of OPC server for help.