On Tuesday, an upgrade was made to all ISI models to separate the WD untrip function from the Saturation Clearing function.  Also, an automated saturation bleed off was included to subtract accumulated saturations over time.  Saturations occuring in a given minute are subtracted from the total 60 minutes later.  This saturation has mainly been an issue for HAM6 when the shutter triggers and jars the ISI table.  While we can accumulate 8192 saturations on the actuators before tripping the ISI Watchdog, hundreds of these saturations can occur for each shutter trigger.

To prevent the ISI from ultimately tripping the ISI, the commissioners added a reset of the watchdog to the guardian.  Since Tuesday, the bleed off has been running but the guardian reset was also operational.  That is, until Sheila commented this out yesterday about 2200utc.  On the attached 24 hour trend of the saturation counter for the HAM6 actuator, I noted the ~time when the guardian reset feature was disabled and the one time when the new CLEAR SATURATIONS button on the watchdog medm was pressed.  You can clearly see the saturations that occur dropping off one hour later.  What is not clear is whether the clearing will happen quickly enough in a state when the system is dropping triggeringthe shutter frequently due to conditions or commissioning activities.  Still, at least here the conditions where such that the saturation were able to get back to zero.

TJ has been tasked with a SYS_DIAG addition to alarm/notify when the saturation total exceeds some percentage of the maximum prompting manual clearing to stop ISI tripping.