Profibus DP Termination Types???


Thread Starter

Brad Wygle

I need some help determining what type of termination to use on an MCC Profibus DP installation. I am advising another engineering company who is insisting on using Active Termination for the Profibus DP. However I have taken the DP/PA course, have spent some time with DP and PA on other installations within Devon Canada and we have never used active termination.

The profibus installation guide indicates active termination is required to maintain segment communication when one slave is disconnected from the segment. However using the DB9 connectors with the built in termination (switched on at ends) the signal is pass through and you can disconnect any slave without disrupting the segment. I have not had any experience with these active terminators and the engineering company's response as to why they should use it is because they used it on the last project and it worked. My concern is that this is adding additional complexity when it is not required.

I believe they are designing for a 1.5M networks and have segments of up to 25 slaves, with a maximum of 50 slaves per DP network.

Appreciate any assistance.