We still see it too, and we do not have any FBMs running ladder logic. We did the isolated-DIN-rail hack that Foxboro recommended but that didn't help. The problem seems to lie in the coax cabling, or the CP's implementation of it**. The best solution for us so far has been to use fiber in the fieldbus network as much as possible. On the installations where we connect the thin white coax from the elevator plugs directly into a fiber converter (the newer Black Box one, not the crappy 1st-gen model that Foxboro initially offered), we see few if any of these errors. Corey Clingo BASF Corp. **Side note: anyone who has ever worked with any kind of coax cable networking knows it's finicky, and I still am incredulous that Foxboro chose to use it when 10baseT (and maybe even 100baseT) was commonplace. From: tjvandew@xxxxxxxxx To: foxboro@xxxxxxxxxxxxx Date: 06/27/2011 09:18 AM Subject: Re: [foxboro] fbm failed messages Sent by: foxboro-bounce@xxxxxxxxxxxxx We saw the intermittent failure and module switch over from fieldbus A to B to A... Also. It appeared to be more prevalent on FBM's running ladder logic, presumably because of increased data load of passing IFL's and OFL's as well as CIN's and COUT's across the fieldbus. If you force the fieldbus to stay on one bus, like A ONLY, the error messages will cease but then you give up bus redundancy for all FBM's attached. If you leave it on two busses it will constantly switch when it hits a COMM ERROR. On one bus it will retry on that bus and doesn't send an error unless it has multiple consecutive failures on that bus. Solution, live with the errors and bus switching or run on one bus only. I don't think Foxboro ever really solved this problem. How about it Dave Caldwell, is this still an issue for you? Tom Vandewater Sent from my Verizon Wireless BlackBerry _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave