Communication between S7-200 CPUSs Thruogh radio link


Thread Starter


Hello , I am Automation engineer , I want to know very deep details regarding using SIEMENS S7-200 in SCADA projects ( using radio link ), such as the protocol, the recommended modems and radios,……….kindly any experienced could help me ……….


Try satel radio modems. They have an interface for profibus-dp and S7-200 can communicate over a DP network. The best solution would be to use S7300 with Siemens SINAUT Telemetry solution. Regards. Omer

Hakan Ozevin

S7-200 has an open communication facility called the freeport mode. You can download examples of it from Hakan Ozevin

David Bergeron

We use S7-200's for SCADA. We have used the S7-214 and S7-224 coupled with Polybus 8175 Bell-202 modem and Dataradio JSLM radio. We will also be using the S7-224 with a Dataradio Integra-TR radio modem. We use the Freeport mode with Modbus protocol programmed in. You could also use the built in PPI protocol but it is limited to 126 addresses. Check out: Polybus makes communications products specifically designed to couple with the S7-200. We had to use the slower Bell202 modem to integrate with existing equipment. But, I would reccomend using a modern radio modem like the Integra if you can. David Bergeron, P.E. Thompson Equipment Co. Phone: 504-833-6381 Fax: 504-831-4664

Talal Kayyali

Dear Mr. Bergeron Kindly , could you tell me how I could build modbus protocol in Freeport mode for the S7-200 CPUs (software) , furthermore I want to know how I specify the signals that to be transmitted to partner in the network and received from any partner in the network . is it possible to send me copy of written software of modbus protocol in Freeport mode for both Master and slave CPU as example to help me ? in advance thank you for your cooperation . regards Talal Kayyali

Michael Griffin

The Modbus driver for the S7-200 is available from Siemens for free. It is somewhere on their web site, it may be present as an example on the CD-ROMs which your programming software came on, and it was on a "demo" CD-ROM called "Tips and Tricks" which Siemens was giving away a while ago to promote the S7-200. I believe the driver was originally written for the older S7-21x series, but it should work with the newer S7-22x series which replaced it. I've never used it, but I recall seeing it in several places. ********************** Michael Griffin London, Ont. Canada [email protected] **********************