Hi Jack, Wow, that bill collector crack perked everyone up. Now for some background. We haven't had a unit trip or transient due to the ZCPs, but we have had a few issues with single switches rebooting, and a couple of years ago had an issue with all the I/O on the ZCPs occasionally and randomly going BAD for one cycle during the seven day hot remarry, which caused control loops to quietly fail to manual. We have fixed that by installing new ZCP images, and adjusting some timeout parameters which we had set much to tightly, but we are still getting some strange FCM messages occasionally on the seven day hot remarry. We've also spent a lot of time setting up our mesh switches, including using VLANs to segregate each ZCP field bus from the mesh, and the more I deal with the switches the more attractive the FCP dedicated field bus looks. Even the high end N1/N3/N7 blade switches are still a commercial network product, and (although we are in this boat now), entrusting my I/O to these switches doesn't give me a warm fuzzy feeling. In my highly paranoid state, I can easily imagine a lot of scenarios where we go to work on a failed switch, and somehow Do Something Bad to the other switch or network. Doing Something Bad typically never ends well. We initially went with the ZCPs in 2005 because we had more than four base plates on several CPs, and had no choice. We have been using FCPs in applications since, and I plan on changing the ZCPs to FCPs/FEMs in the future, just to get rid of the potentially nasty failure modes associated with the switch failures. The FCPs are just so much easier to deal with all around. Thanks, Gaylon Hicks TVA - Browns Ferry -----Original Message----- From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On Behalf Of Easley, Jack Sent: Wednesday, November 10, 2010 3:46 PM To: foxboro@xxxxxxxxxxxxx Subject: Re: [foxboro] One Mesh vs Multimesh Just wondering what issues you've had with ZCP270s as we've had none in the past 4 years, although we do realize going forward that FCP270s are best (but were not originally due to limited number of FBMs). Jack Easley Sr. I&C Technician Luminant Power, Martin Lake Plant Phone 903.836.6290 jack.easley@xxxxxxxxxxxx -----Original Message----- From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On Behalf Of Hicks, Gaylon F Sent: Tuesday, November 09, 2010 11:32 AM To: foxboro@xxxxxxxxxxxxx Subject: Re: [foxboro] One Mesh vs Multimesh Worst case you only crash everything on one Unit with multiple networks, but it will cost you more in hardware. We rigorously separate our units, but then we're a nuke. It's still a good idea. My best advice for mesh architecture is to make sure you can tolerate a complete failure. Avoid ZCPs like they're a bill collector. Gaylon Hicks TVA - Browns Ferry -----Original Message----- From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On Behalf Of Olsson, Scott Sent: Tuesday, November 09, 2010 11:14 AM To: foxboro@xxxxxxxxxxxxx Subject: [foxboro] One Mesh vs Multimesh What are the Advantages and Disadvantages of 1 Mesh for the entire Plant vs a Mesh for each Unit Scott Olsson PNM Resources _______________________________________________________________________ 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