My project requires 2 Siemens S7-200 in different sites to communicate (exchange data) to each other. The communication media used is leased line and a pair of modems. Since I have no experience in programming PLC to communicate via modem, if anybody has such experience or even has a sample program of similar application, please give me some hints or advice, a sample program will be very welcomed and will definitely help me a lot. Thanks.

 

Look on Siemens web site

http://www.aut.sea.siemens.com/controls/other/s7-200/
for the S7-200 Tips and Tricks document(s). It has many example programs for S7-200, several of which deal with modems. I have used the S7-200 with dial-up modems and it works fine. You can even use the Freeport mode to develop your own protocol.

Chester Marshall
Arkansas Industrial Computing