Thanks for all the great replies. We knew about the OSV, but the = problem we had with that was, where is the right setting? I guess using = a rule-of-thumb value of 10% will be OK for most transmitters, but we're = still leery of a transmitter failing at say, 3% or 5% below or above = range, and the system not registering that as bad and the controller = being happy with a bad measurement. Every transmitter, or at least = every transmitter type, is different at the mA value where it actually = fails, and it's going to take some effort to keep after that OSV = parameter for each individual transmitter through routine maintenance = and turnarounds. The CEOPT parameter in the PIDA looks like the answer. I had never done = any research on this one before. It sort of showed up in version 4.x or = 5.x and I never really paid much attention to it. We tested it out this = morning, and it looks like setting it to 2 will do what we need. I = think combining setting the CEOPT to 2 with raising the OSV slightly or = maybe researching where at least the most critical transmitters actually = fail is the best solution. Thanks again for all the help. Tim Lowell Control Systems Engineer ConocoPhillips, Trainer Refinery Phone: 610-364-8362 Fax: 610-364-8211 Tim.C.Lowell@xxxxxxxxxxxxxxxxxx _______________________________________________________________________ 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