Profibus connectors


Gabriele Corrieri


Profibus connector (I think that you write about 9 pins one) are simple DB-9 male connector (some with female replication on back side) with termination network. Plain text email aren't good for show look at:

The Data Ground is 5, +5V is 6, Line A is 8, Line B is 3.

You can weld by yourself connectors and termination networks, but with network speed great than 1Mbps (IMHO) your connector need a pair of little inductances from in series to A and B signals for more squaring data lines. At speed up to 187,5 Kbps, and little network the termination could be not necessary (again IMHO).

I'm writing my 15-years know how about profibus copper network (little and large ones) making, commissioning, and fault-finding, someone could have a different idea about connectors,the much simple way if you won't trouble could be buying profibus connector from one of dozens that make them, but if you want to know how it work you must make your own and test'em.


Gabriele Corrieri

James Ingraham

Connectors specifically designed for Profibus, of course. The standard Profibus connector is 9-pin D-Sub. (Only three pins are actually used, and one of them is the shield.) There is also an M-12 round connector. So why not just use any old 9-pin D-sub or M12? Because Profibus, particularly at higher speeds, is very finicky. I wouldn't say it won't work; it might. But if you're building a Profibus network you probably want to use Profibus-specific connectors. If nothing else, if there is any sort of a problem, people won't immediately think it's your fault for using non-standard connectors.

-James Ingraham
Sage Automation, Inc.

curt wuollet

Some of the "no-tools" profibus connectors are more of a liability than an asset. If there was a good way to clamp the shields, I think hand assembled and soldered or at least crimped, would be far more reliable. But they do have some passive components in the plugs I've seen, they aren't just a connector. I have fixed most of the profibus problems I've encountered by reworking or replacing the connectors, occasionally a cable would get pinched. I hold IDCs to be only a short term connection in most industrial environments. I worked on a very large printing machine that used hundreds of IDC ribbon connectors. After a few years that machine had a different set of problems every day and they would come and go because at any given moment, one or more of those pressure connections would be open. The screw clamp type are better if you value your sanity. At least these types of failures aren't too difficult to track down. But if the Profibus club really wants to obsess on certification, these connectors would be a good place to start. In most cases these are a single point of failure for the whole network and the whole machine.