Sending and receiving SMS with Siemens S7-200

Hi!
I’m learning to send SMS with a GSM modem and a S7-200 PLC of Siemens. It’s hard but I think it will be done one day J.
My customer is asking me if is it possible to send a SMS to the PLC asking it about the state of the instalation. With this task I feel a little bit lost. Could anybody give me some information about this, or send me an example of program J?

Thank you very much,
David

Do it yourself or download it!

Hi David:

There is 2 ways for receiving SMS with a modem GSM and a S7-200.

1. You can configure the modem to tell the PLC when a SMS is just received.
2. You configure the modem to store the SMS and is the PLC who ask him about incoming SMS.

I think the second is better because you will not have unexpecting comunications from the modem in the freeport comunication. The configuration for this is AT+CNMI=0,0,0,0.

In this case you must ask periodically the modem if there are any new SMS. The AT command for read the SMS is AT+CMGR=1 (to read in the inbox 1). And use AT+CMGD=1 to delete it after reading. You will get the SMS in the V memory and after that you will be able to analyze it!

If at the end you find it very hard to get success, there is a library for STEP7-MicroWIN that solves it very easy. You can test it for free. Look at www.nubitek.com and download Nubitek_SMS_Manager.

Regards

Lorenzo Rivas