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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: 11849     Entry time: Fri Dec 4 18:20:36 2015     In reply to: 11844     Reply to this: 11854
Author: gautam 
Type: Update 
Category: CDS 
Subject: BLRMS for IMC setup 

[ericq, gautam]

BLRMS filters have been set up for the coil outputs and shadow sensor signals. The signals are sent to the C1PEM model from C1MCS, where I use the library block mentioned in the previous elog to put the filters in place. Some preliminary observations:

  1. The entire operation seems to be computationally quite expensive - just for the 3 IMC mirrors, the average CPU time for C1PEM increased from ~50 usec (before any changes were made to C1PEM) to ~105 usec just as a result of installing 420 filter modules with no filter coefficients loaded (3 optics x 10 channels x 14 filter banks) to ~120 usec when all the BP and LP filters for the BLRMS blocks have been loaded and turned on (Attachment #1). Eric suggested that it may be computationally more efficient to do this without using the BLRMS library part - i.e. rather than having so many filter modules, do the RMS-ing using a piece of C code that essentially just implements the same SOS filters that FOTON generates, I will work on setting this up and checking if it makes a difference. The fact that just having empty filter modules in the model almost doubled the computation time suggests that this approach may help, but I have to think about how to implement some of the automatic checks that having a filter bank in place gives us, or if these are strictly necessary at all...
  2. While restarting the C1PEM model, we noticed that some of the optics were shaking - looking at the CPU timing signals for all the models on C1SUS revealed that both the C1SUS model and the C1MCS model were geting overclocked when C1PEM was killed (see the sharp spikes in the red and green traces in Attachment #2 - the Y scale in this plot is poor and doesnt put numbers to the overclocking, I will upload a better screenshot that Eric took once I find it). The cause is unknown.
  3. Yesterday, I noticed that when C1PEM was restarted, the states of the filter bank switches were not reverted to their states in the SDF tables. They are showing up as changes, but it is unclear why we have to manually revert them. I have also not yet added the states of the newly installed filters (BPs and LPs for the MC BLRMS blocks) to the SDF tables. 

Unrelated to this work: we cleaned up the correspondence between the accelerometer numbers and channels in the C1PEM model. Also, the 3 unused ADC blocks in C1PEM (ADC0, ADC1 and ADC2) are required and cannot be removed as the ADC blocks have to be numbered sequentially and the signals needed in C1PEM come from ADC3 (as we found out when we tried recompiling the model after deleting these blocks).

Attachment 1: c1pem_timing.png  47 kB  | Hide | Hide all
Attachment 2: C1SUS_overclocked.png  20 kB  | Hide | Hide all
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