WP #5618  Rezero ETMY STS2

Jim noted in the LHO alog 23610 that blend switching is smooth for most BSC platforms except ETMY.  BTLantz noted that the ETMY STS2 was not well centered and Jim thought this may contribute to the blend switch glitch, hence the work permit.  Enter me.

At the EndY, I ramped down the sensor correction and then got distracted with something shiny and started looking at the front panel UVW monitors.  Toggling the UVW/XYZ selector on the STS2 does not impact the signal going into the STSINF but when I toggled the T240 selector, the ISI tripped.  Karen was around cleaning at the time but I suspect it was me.  So with DVM I checked the T240 monitors and saw a few of the 9 (three t240 x U V & W) reading as high as 6+V.  Some were mvolt level.  Now I rezero'd all the T240 with selector in UVW position.  Now all read < ~200mvolt.  Toggle back to XYZ position.

Sensor correction ramped back on and ISI reisolated.  Yes, did you note the glaring ommission?  Yes I never did rezero the STS2, rats ankles!

Attached is the T240 X Y Z  INMONs where the ISI trip and the zeroing are evident on this 1 hour long trend plot.

The second attachment is the T240 U V W monitors.  Again very evident is the ISI trip and the rezero.  Yes, very interesting...

The X Y Z signals all return to about where they started.  I did zoom into them all and they are a little different but pretty much zero before zero after.  The U V W trends though show a much different story.  Six of the nine channels show a large step toward zero with the reset.  The other three basically return to where they started after the rezero action.  Still at least now, the six channels that were many thousands are now all under 1000 and only one channel of the nine remains above 1000.  Maybe the blend switching will be smoother now.  Maybe this rezeroing needs to be repeated to encourage the remaining to get closer to zero.