Hi,
It is not very clear from BOL where the cable shield should be connected. For now, we have like this:
Left card is H1 with integrated power and the right one is the Profibus (the card is sitting at the middle of the segment with its terminator OFF).
It is clear that in the case of the H1 card, the shield has to be connected at one point, and that point is the ground bar of the 8-wide carrier (this in turn has to be connected to ground).
But for Profibus my research was inconclusive: should it be connected also to the ground bar of the 8-wide carrier or should it be connected to terminal "S" of the Profibus card (as shown on the picture)?
Could someone clarify this?
Thank you,
Istvan
Hi
Sorry, no special experience with Profibus wiring, but, if that can help, remember that cable shield must be connected to (electronic) ground only at ONE side.
If you connect shield by both cable sides, you will create a capacitor !
Choose the side where the ground have the best quality.
In reply to Jack_France:
Check, but I believe I saw 0 Ohms between the S and ground bar, so I'm going to assume it doesn't matter. I understand the confusion, as the BOL picture shows the S terminal isolated.
The Profibus Installation Guide (clips below) does recommend grounding on both ends, but not when connected to IS systems.
In reply to Travis Neale:
The DeltaV Technical Documentation team saw this thread and made some updates to this section of DeltaV Books On-line. I wanted to share this advanced copy with members of this track.