Sheila, Richard,
Filiberto and Richard installed new noise monitor circuits on the ETM PUMs last week, this morning I measured some transfer functions of them.
Attached are the dtt templates. Unfortunately I measured these TFs with the coil driver in state 3, which means that the low pass is on and the acq filter is off (the acq filter is after the noisemon pick off). In the digital noisemon filters I used the ANTILP filter zpk([0.4915;240.0583],[5.4697;21.8761],1,"n").
I'm also attaching the ITM measurements, which were taken in the same configuation 54614
The transfer function for ETMY LL seems significantly different from the rest. Richard and I set the test/coil enable to 0 (seting the driver into test mode, which means no input from DAC, I'm not sure what it means about terminating or floating inputs) and looked at spectra, and LL also looks different (3rd screenshot).
Richard is heading to the end station to check if there is something like a capacitor that wasn't swapped in that channel.
The EE team did find a bad solder joint in the ETMY LL channel, and repaired it before the end of maintence. Richard also re-ran the set of transfer functions for the noise monitors for EY, the attached file has his new set of measurements. The quadrants all seem to be the same now.
This ETMY measurement was taken with coil drivers in state 2, but the antiLP filter was on. That means that to compare these TFs to the others, we need to remove the filter zpk([0.4915;240.0583],[5.4697;21.8761],1,"n").
Attached are filters to calibrate the noisemon outputs in DAC counts.
They are designed by fitting the above-measured transfer functions (using IIRrational) and then inverting them. The antiLP filter was removed from the ETMY data. Poles at very low frequencies were nudged up to 1 Hz to limit the DC gain.
Attachment 1: plots of the data and fitted filters.
Attachment 2: filter install script
Thank you very much Chris.
I have just run this script and turned on the new filters, because we are out of observing for ~40 minutes of commisioning time. The new filters are turned on as of 20:22 UTC Feb 13, so the noise mon channels are all calibrated into DAC counts now.