Looked at time series and of course suspecting the actual tilting found coherance between the T240 and the HEPI IPS--See first plot.  The Coherence plot is from the tilt period; untilted shows the same coherence--near 1 from 10 to 100mHz.  The power spectra show the increase power in IPS_RY when tilted (ref-brown) relative to the non-tilted IPS and the tilted IPS_RX--we aren't tilting RX.  Like wise the upper right graph shows the elevated noise in X_T240:

The noise in RY IPS becomes noise in the T240 X as the T240 is so very sensitive to tilt.  So HEPI is doing this to the T240 when HEPI tilts.  Why?  Just the large drive from zero?  Remember, this HEPI is not yet commissioned and this tilt is just open loop...

Looked at the HEPI Pump next.  See the second plot below.  This shows a few days where there was some long stretches of either HEPI Tilted or not.  In the two left graphs are the same IPS signal and I've zoomed into the non-tilted and tilted times and seen by the magnitude of the numbers.  The zoom scale is the same and the elevated noise here is apparent.  The two right graphs are the HEPI Pump Station Output Pressure and the controller output to the pump motor.  There are some transistion glitches during the large changes to tilt the HEPI and the control output changes to deal with the different valve position at the Actuators (Maybe?) but otherwise, the pressure and control are not noisier during the tilted HEPI.

Looked at zoomed in time of IPS tilt and the pump control.  See third plot.  I've offset and scaled the curves to get them to show on the same plot.  I'll look at more case of T240 glitches(excursions) but I think this plot suggests a correlation of large fluctuations of the Pump pressure (I know I plotted the control but it is similar) to the excursions of the IPS and ultimately tripping the ISI from T240 triggers.