GPRS for two way SCADA applications

GPRS usage for two way SCADA communications applications - slave to master is understandable in a way that the slave with GPRS connectivity (and a dynamic IP address of course!) will log on to a static server's IP address (that of the master with a static IP address provided by the Internet Service Provider) and pushes the data to the master. However, the master to slave (RTU) communication is not possible without a static IP address within the slave. This is being achieved through SMS (control signal command) from master to slave on its MIN (Mobile Identification Number).

I would like to understand how this is done, and if there is a possibility of Master/Slave communication without the SMS route and without a static IP address at the slave.

Thanks in advance.

<I would like to understand how this is done, and if there is a possibility of Master/Slave communication without the SMS route and without a static IP address at the slave.>

That is a very good question. I also would like to know the answer to that.

The only way I see this happening is if the device with a dynamic IP address (slave in your example) has the ability to associate with some DDNS (Dynamic DNS) service. Then the master would use the hostname of the slave as apposed to the IP address. Providing the master supports using hostnames, of course.

Hello,

Go to controltoolbox.com and read NetPro-ModServ developer's manual. The remote does not need to have static IP address while the communication is two-way. In a nut-shell, the commands are polled by the remote with a proper timeout to avoid loading the channel.

Rod