Hi all, We've had this in the past multiple times. It also happened with Reals BTW, not only with Booleans. Alex's procedure usually solved it, but one time we had to call the service guys in to solve it. I think we had to reboot the CPs then. Rebooting CP's is the last resort off course, nobody in his right mind would reboot CP's during production.... We've also had PLB blocks that stopped working, but a delete/ undelete always solves that, reason again unknown..... I was told the P2P problem can occur if you create and delete tags in the same session, so now I usually checkpoint in between deleting and creating tags and we haven't had it since, but this could be coincidence. It's not a very comforting idea to run a chemical plant with lots of automation, exotherm's in several reactors... and unreliable P2P connections. It can get very scary and messy..... I try to avoid P2P connections as much as possible, but sometimes it's necessary. I use Ain's which check for P2P errors, (station.PP_DEL, PP_DSC, PP_NFD) with an alarm threshold of 1, if there are any, I'm notified by mail and with a notification alarm, but I seem to recall the frozen P2P connections were not reported as P2P errors, because the connection was not broken, it was simply not updating, so this doesn't help much. Running Rsom on a very regular base might help some, but even then we can have problems caused by stale tags in a matter of minutes, so it's not a solution.... Maybe someone could develop something like a constantly running Rsom, with reporting and notification capability that doesn't take much server processor capability? Rgds, Dirk _______________________________________________________________________ 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