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Entry  Tue Dec 1 17:16:31 2015, gautam, Update, CDS, Script for copying BLRMS filters makeFilterFiles.bash.zip
    Reply  Wed Dec 2 18:54:20 2015, gautam, Update, CDS, Changes to C1MCS, C1PEM  
       Reply  Thu Dec 3 18:18:48 2015, gautam, Update, CDS, BLRMS for optics suspensions - library block 
          Reply  Fri Dec 4 18:20:36 2015, gautam, Update, CDS, BLRMS for IMC setup c1pem_timing.pngC1SUS_overclocked.png
             Reply  Mon Dec 7 00:45:28 2015, ericq, Update, CDS, daqd is mad 
                Reply  Mon Dec 7 10:45:21 2015, ericq, Update, CDS, daqd is mad 
                   Reply  Mon Dec 7 11:25:10 2015, jamie, Update, CDS, daqd is mad 
                   Reply  Mon Dec 14 23:56:29 2015, ericq, Update, CDS, c1pem reverted 
          Reply  Tue Apr 5 14:16:34 2016, gautam, Update, CDS, BLRMS for optics suspensions - library block UPDATED 
             Reply  Wed Nov 2 22:56:45 2016, gautam, Update, CDS, c1pem revamped 
                Reply  Thu Nov 3 12:38:42 2016, gautam, Update, CDS, c1pem revamped BLRMSresp.pdf
                   Reply  Thu Nov 3 13:36:16 2016, ericq, Update, CDS, c1pem revamped 
                   Reply  Fri Jan 27 21:21:35 2017, gautam, Update, CDS, c1pem revamped 
Message ID: 11840     Entry time: Wed Dec 2 18:54:20 2015     In reply to: 11833     Reply to this: 11844
Author: gautam 
Type: Update 
Category: CDS 
Subject: Changes to C1MCS, C1PEM  


I've made several changes to the C1MCS model and C1PEM model, and have installed BLRMS filters for the MC mirror coils, which are now running. The main idea behind this test was to see how much CPU time was added as a result of setting up IPC channels to take the signals from C1MCS to C1PEM (where the BLRMS filtering happens) - I checked the average CPU time before and after installing the BLRMS filters, and saw that the increase was about 1 usec for 15 IPC channels installed (it increased from ~27usec to 28usec). A direct scaling would suggest that setting up the BLRMS for the vertex optics might push the c1sus model close to timing out - it is at ~50usec right now, and I would need, per optic, 12 IPC channels, and so for the 5 vertex optics, this would suggest that the CPU timing would be ~55usecI have not committed either of the changed models to the SVN just yet


  1. On Eric's suggestion, I edited the C1_SUS_SINGLE_CONTROL library part to tap the signal at the input to the output filters to the coils, as this is what we want the BLRMS of. I essentially added 5 more outputs to this part, one for each of the coils, and they are named ULIn etc to differentiate it from the signal after the output filters. I have not committed the changed library part to the SVN just yet
  2. I used the cdsIPCx_SHMEM part to pipe the signals from C1MCS to C1PEM - a total of 15 such channels were required for the three IMC mirrors.
  3. I added the same cdsIPCx_SHMEM parts to the C1PEM model in the receiving configuration, and connected their outputs to BLRMS blocks. The BLRMS blocks themselves are named as RMS_MC2_UL_COIL_IN and so on.
  4. I shutdown the watchdogs to MC1, MC2 and MC3, and restarted the C1PEM and C1MCS models on C1SUS. Yutaro pointed out that on restarting C1MCS, the IMC autolocker was disabled by default - I have enabled it again manually.
  5. I was under the impression that each time a BLRMS block is added, a filter bank is automatically added to the C1PEM.txt file in /opt/rtcds/caltech/c1/chans - turns out, it doesn't and my script for copying the template bandpass and lowpass filtes into the .txt files was needlessly complicated. It suffices to change the filter names in the template file, and append the template file to C1PEM.txt using the cat command: i.e. cat template.txt > C1PEM.txt. The computer generated file seems to organize the filters in alphabetical order, and my approach obviously does not do so, but the coefficients are loaded correctlty and the filters seem to be functioning correctly so I don't think this is a problem (I measured the transfer function of one of the filters with DTT, it seems to match up well with the Foton bode plot). 
  6. I added a few lines to the script to also turn on the filter switches after loading the filter coefficients.

Next steps:

Now that I have a procedure in place to install the BLRMS filters, we can do so for other channels as well, such as for the coils and Oplevs of the vertex optics, and the remaining PEM channels (SEIS, accelerometers, microphones?). For the vertex optics though, I am not sure if we need to do some rearrangement to the c1sus model to make sure it does not time out...

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