Connect Sinamics DCM with both Profinet and Profibus

Hello to all,

I have an application I am attempting to develop and could use some guidance.

At this time I have two 6RA80 drives with CBE20 communications cards. The first installation is 7 years old; the drives are controlled by discrete signals generated by an Allen-Bradley ControlLogix PLC. However, drive status is communicated to the PLC via Ethernet/IP. The two drives exchange process data via a Peer to Peer connection, at 187500 baud. Only 4 words are exchanged, in order to get the fastest exchange possible. I would like to have a bit faster data transfer; however, this has worked will enough to not require modification.

Now I am looking at a similar application, where there would be four drives, which would also have the CBE20 communications card. The drives would be controlled via Profinet, with "Control by PLC". However, the drives will also have the requirement of exchanging process data between each other (but not the PLC). I am considering using Profibus, via IF2 for this purpose. If each drive also provides 4 data words, this would be a total of only 16. I see that IF2 has the capacity for up to 64 send or receive words.

I was thinking I could use a CP5711 to access the Profibus network. The data being exchanged between the drives does not need to be sent through the PLC.

Does this sound plausible? Any suggestions would be appreciated.

Hello,

In general it seems possible, but accordig to the FAQ (https://support.industry.siemens.com/cs/ww/en/view/17660809) the CP5711 isn't able to support direct data exchange, what is necessarry, even if it will not receive/send any data itself.
However with using S7-300 PLC it is possible to engineer the direct data exchange, but with CP5711 the register "direct data exchange" is for example not present in STEP7 hardware configuration.

As alternative you maybe can think of using PROFIBUS for control the drive and using CBE20 with SINAMICS Link for data exchange between the CUs. Depending on your needs you can run drive control (via PROFIBUS) or SINAIMCS Link in isochronous mode (p8812=1).

The "Parallel operation of communication interfaces" as well as SINAMICS Link with DCM are described in manual https://support.industry.siemens.com/cs/ww/en/view/109763559