How to write Modbus RTU protocol command?

Question

Modbus

Help me read the data registers :)
There is such a device
that works according to the Modbus RTU protocol, it is connected via RS-485 to the GPRS modem on the SIM card. There is a static IP address.
The question is how to read data from the register. Those. through what software or cmd, terminal?
How to write a query, preferably an example.

Answer 1

It is not clear how the device transmits data via a SIM card (by what protocol), otherwise you take any scada with the support of the desired driver (modbus tcp, modbus rtu) and read the data, for example MasterScada.