For the record, the above mentioned DAC recalibrations did NOT solve any of the problems that have reared up over the weekend. I can, however, report that the auto-calibration was successful for all DAC cards that were restarted.

The 3rd DAC card's calibration on h1sush2a succeeded slowly, as it has done previously both on Aug 03 2015 (LHO aLOG 20165), and the time prior, Jun 09 2015 (LHO aLOG 19030). As reported before, this DAC card controls PRM M1 RT and SD. Last six channels are PR3 M1 T1, T2, T3, LF, RT, SD. Also as reported before, we don't know what this means or if it is significant.

HOWEVER, according to what tests we have done, this DAC card being slow is merely coincidental with the problems we've been having with the PRM LF RT and PR3 T1 T2 noise found on those OSEM sensors. We've confirmed this by measuring the ASD of the OSEM sensors (as Evan has done in LHO aLOG 21056) with the suspension in SAFE (i.e. no requested drive) and found the noise as expected. We then switched the TEST/COIL enable switch to removed the DAC's ability to drive by removing the DAC input to the coil driver. The noise remained.

The investigation continues...

For h1sush2a (which houses MC1, MC3, PRM, and PR3):
[8808794.054622] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[8808799.414955] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[8808806.438391] h1iopsush2a: DAC AUTOCAL SUCCESS in 6572 milliseconds 
[8808811.798720] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[8808817.586599] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[8808822.947012] h1iopsush2a: DAC AUTOCAL SUCCESS in 5345 milliseconds 
[8808828.307368] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds 
the last time these DACs were recalibrated was Aug 03 2015.


For h1sush2a (which houses SRM, SR3, and OMC):
[5345389.136545] h1iopsush56: DAC AUTOCAL SUCCESS in 5333 milliseconds 
[5345394.496918] h1iopsush56: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[5345400.284896] h1iopsush56: DAC AUTOCAL SUCCESS in 5341 milliseconds 
[5345405.645225] h1iopsush56: DAC AUTOCAL SUCCESS in 5344 milliseconds 
[5345411.433249] h1iopsush56: DAC AUTOCAL SUCCESS in 5341 milliseconds
the last time these DACs were recalibrated was Aug 18 2015 (LHO aLOG 20631)