David logged about the SUS IOP glitches generating IPC errors to SEI Tuesday. These sometimes (too often) would trip the ISI. SEI has a solution already for the HAM ISIs which Jim detailed in 19842 where we added it to the BSC ISI.
Attached is a duplicate of David's plot from Tuesday. This is 14 days and clearly the ISI TRIP FLAG (UpperLeft) which became very active after the SUS computer upgrade is now back to quietly sitting at zero. The trip flag doesn't always register when a glitch from the SUS occurs(UpperRight and LowerLeft) but things do look better now. A repeat of this in a few more days will prove it pretty convincingly. The ISI has had a few trips since the model change but not from the SUS.