Hi experts,

We have to transfer process data from a remote site about 120km away to plant control room. I got hold of two Westermo GDW-11 modems to be used in GPRS mode connected to serial port of ControlLogix controllers. I also got two SIM cards from local service provider having fixed (static) IP addresses.

Currently, I am testing these modems with GD-Tool application supplied by Westermo. Two modems can ping each other but I don't know which commands to use to send the some process data like bit status and flow, pressure data. I want to accomplish this task with GD-Tool first and then move forward to connect these modems to PLC serial port and issue ASCII commands from there.

Please advise how can I accomplish this task.

 

Hi,

First, if you use GPRS the distance have no limits (if your GSM provider have signal).

Second you have to wrap the ascii protocol in Ethernet, likewise you can use the ascii to IP converter maybe mmnet01.

Regards,
Andrzej,
www.modbus.pl

 

@Andrzej

The reason I wrote 120km was to inform that direct communication link would be highly expensive that is why we are going to use GPRS.

PLC can issue ASCII commands from its serial port. Why do I need a converter?

Please help guys.