Communication between S7 and MCD3000 (Danfoss)


Thread Starter


Does anybody know that it is possible to exchange data between S7 PLC and MCD3000 (Danfoss Softstart) using ASCII and RS-485?
Is anybody who made connection between that devices??
I found description of protocol in Danfoss documentation, so there is no problem with protocol, but I am afraid about dynamic. Danfoss communication equipment is faster than program in PLC, so some information could be lost.

Best regards

Andrew Hawdon


with Step 7 typicaly you would use a CP340 as the communication card in the rack. The CP handles the communication and passes the data to the PLC. It also supports a number of standard protocols as well as ASCII. I would suggest that you download the documentation from the siemens web site ( and have a look at the modules capabilities. I do not know much about the MCD3000 but in my experiance this card will communicate with most other devices if they are both using ASCII you may just have to build in some handshaking.

Hello other possibility, is to make communication with profibus net, I think cp340 can work with profibus.
Profibus would be great for me, but MCD3000 doesn't make possible communication by Profibus. It has own protocol based on ASCII codes.


Eduardo Suarez

One posibility is to use a gateway if you want I can send you information, just send me a email.