Communication / Networks

Piggyback Connector

Thread Starter: MemoGG   Started: 8/16/2012 9:43 PM   Replies: 3

  8/16/2012, 9:43 PM

MemoGG Joined 2/20/2009 Last visit: 5/14/2013 Posts: 49 Rating:  (0)

(0)  Hello Everybody, I hope you could help me with the following question, I have a profibus network, and the segment goes from an OLM to a simocode node (passing thru several simocodes, less than 30), both ends terminated. To diagnose the network there is a pigggyback connector at the OLM where we connect a small cable (8 inch long) which has another piggyback connector with a terminating resistor lever. My question is if we need to terminate the the latter piggyback connector (the one at the small cable) or not. The OLM end is already terminated as I pointed out. Another doubt is if a piggyback connector 'creates' a spur line wherever in the network is used (this could answer my first question, too). Regards

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  8/16/2012, 10:05 PM

dchartier Joined 9/27/2006 Last visit: 5/24/2013 Posts: 3949 Rating:  (620)	(0)  Hello Memo; You do not need to termiante a spur-line, especially if it is so short (8 in.). Hope this helps, Daniel Chartier
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  8/17/2012, 9:03 PM

MemoGG Joined 2/20/2009 Last visit: 5/14/2013 Posts: 49 Rating:  (0)	(0)  Thanks for your reply, Daniel. Just one more thing, does the cable attached to the piggyback connector at the end of a segment acts as a spur line? (I think so but I am not quite sure) Regards
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  8/17/2012, 10:25 PM

dchartier Joined 9/27/2006 Last visit: 5/24/2013 Posts: 3949 Rating:  (620)	(0)  Hello memo; By definition, a spurline is a cable that connects any instrument to the main truckline of a daisy-chained network, such as Profibus. Profibus-DP is not comfortable with them, so you should really keep them as short as physically possible. Profibus-PA has a different physical layer and accepts the spurs very naturally. Hope this helps, Daniel Chartier.
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