It recently turned out that switching blends was causing glitches in the blend output to the servo loops, which were tripping the ISIs. The script handling the transition between blend filters was modified to provide a smoother ramp and prevent WD trips.

After testing at MIT, HAM and BSC master models were updated here. Every ISI on site was recompiled and restarted. The new blend switching was tested by using the blend switchall buttons* on BSC-EX. It works as expected. I was able to do the following blend switchall without tripping the ISI:

• Start->TCrappy
• TCrappy->TBetter
• Tbetter->Start (T240s rang up a bit, but they were already off the servo loops, and their WD threshold was still up from turning the ISI on earlier)

Work was performed under WP 4568, which is now closed.

*:one button to switch every blend filter of a stage a once

Note: ITMY foton file turned out to be corrupted. We only found out after restarting the model because the corrupted foton file never got loaded in the first place. Please make sure that anytime you update a Foton file, you push the Coeff load button in the GDS-TP screen. Please note that pushing the Coeff Load button from individual filter banks does not create a backup foton file, which pushing the same button from the GDS-TP sceen does.