J. Kissel, T. Sanchez, L. Dartez

As we began to use the new OMC DCPD test infrastructure (LHO:78956, LHO:78975) to pick up where we left off in characterizing the new-to-O4, segregated OMC DCPD, 524 kHz low-noise ADC system (LHO:78516, LHO:78559), we found in necessary and fruitful to
 
- shift some of the installed filters around in the A2 and B2 banks (the one's the replicate the reverse-calibration filters that turn the raw ADC counts in mA on the DCPDs; the copies of the A0 and B0 "NewV2A" and "NewAW" -- moved from FM1 and FM2 to FM2 and FM3 like they are in the A1 and B1 banks.)

- add the 1 Hz 5th order elliptic high-pass as an option to the A2 and B2 filters in FM1 (like the A1 and B1 banks) and 

- split out "divide-by-four" gain of 1/4 that turns the sum of the four channels into an average from the "cts2V" ADC calibrating gain of 40 / 2^18 [V/ct] = 0.00015258789 [V/ct] ~ 0.0001526. The ADC gain in th previous cts2V bank was actually implemented as a typo of the 16 bit ADC calibration divided by 4. The ADC gain should be 40 / 2^16 [V/ct] = 0.00061035156 [V/ct], but was installed as 0.0006105 "[V/ct]." And then the multiplication of the gain of 1/2^2 = 1/4 = gain(0.25) to convert from 16-bit to 18-bit calibration was immediately adjacent to the gain(0.25) for turning the sum into an average. Not so clear.

So, what was 
    cts2V = gain(0.0006105)*gain(0.25)*gain(0.25)
in FM4, is now two separate filter banks
    18b_cts2V = gain(0.0001526)
    sum2avg = gain(0.25)
in FM4 and FM5.

The new filter banks and arrangement have been committed to the SVN under 
    /opt/rtcds/userapps/release/cds/h1/filterfiles/
        H1IOPOMC0.txt       rev 30385

Also -- it appears as though the B1 and B2 filter banks didn't have their filters properly *un*monitored when I touched the SDF system last week (LHO:82155). The configuration changes (made during Monday commissioning time) thus had prevented returning to observing. I've rectified that as well, so now, *really* these A1, A2, B1, and B2 banks' EPICs records can be changed at will during observing.