Profibus DP Installation: Connect/joint profibus cable

A

Thread Starter

Amir Farid

Hello Everyone or Profibus Maestro...

I would like to understand the correct way or the best method to make connection/join of Profibus cable connection.

Basically, base on current arrangement that we have, the connection/join of profibus cable is done over the normal wire terminal. Is like to make connection between field wire from outside of the junction box to internal wiring in the junction box.

Really appreciate, if someone can advice me if profibus also can be connected with the same way, and if it is not.. please help me to support this with some reference or document.

I really one to understand how this kind of connection can cause interference to the signal or distort the profibus communication characteristic.

Please advice.
 
I am not sure I understand. Are you taking 2 separate cables and using a coupler? If so, it is surely best to have one straight-thru cable.

Either way, Profibus can tolerate some interference when using the lower baudrates. What baudrate are you using?

The higher baudrates (above 1.5MBaud) are more likely to have issues with reflections and/or attenuation.

So if you find yourself with communication errors, try dropping your baudrate.
 
J

James Ingraham

I have personally seen Profibus wired to terminal blocks work just fine. I have personally seen Profibus wired perfectly (at least in theory) not work at all. Profibus is very finicky. I do not recommend doing what you're suggesting. My own way of handling this is to use two M12 Profibus-rated field-wireable connectors. Yes, even inside a junction box. You could alternately use a standard DB9 Profibus connector, but then people will wonder why the heck there is a Profibus connector in a junction box not hooked up to anything.

As Simon said, baud rate matters. I don't think I ever managed to get a Profibus network running at 12Mbps. 1.5 Mbps is as fast as I would ever recommend.

Hope that helps.

-James Ingraham
Sage Automatin, Inc.
 
Top