Since there seem to be some confusions about which PD has what kind of analog filtering and sent to which channel, here it is.
I'm quite certain about HPO output before AOM (which is "Power monitor PD" in D1002929) and ISS 1st loop monitors, but not that sure about "monitor PD"s in D1002164. E-travellers are incomplete (they don't say which one is installed where), so I'm just listing the nominal values for these "monitor PD"s.
| What | PD name on D0902114 | Circuit type | Analog out | Transimpedance (Ohm) | Analog filter | Channel | Note | Can you find Filter MEDM from sitemap as of this writing? |
| HPO output before AOM | PD1 |
Power monitor PD, D1002929 |
DC | 3.3k DC |
H1:PSL-PWR_HPL_DC, DC_LF |
DC_LF is digital downstream of DC, EPICS output is visible as "Power Monitor PD" on PSL_LASER MEDM. |
No | |
| AC | 16.5k AC | 5k HPF nominal | H1:PSL-PWR_HPL_AC | No | ||||
| ISS 1st loop diodes after PMC | ISS_PDA, ISS_PDB |
Inner loop diodes, D1001998 |
"Filt" on the board, "AC" on the box | 660 DC |
z=[0.0723;2700;0.0707] Hz, p=[3.3607;130;3.12;2300] |
H1:PSL-ISS_PDA and PDB |
No dewhite, output is calibrated in volts. |
No |
|
H1:PSL-ISS_PDA_DC and PDB_DC |
Digitally low-passed version of PDA and PDB, but has a DC gain of 5 so the DC agrees with the analog of "DC" output on the PD box. | Yes, from ISS | ||||||
| H1:PSL-ISS_PDA_AC and PDB_AC | Dewhitened and AC-coupled version of PDA and PDB, has a gain to match PDA_DC and PDB_DC | Yes, from ISS | ||||||
| H1:PSL-ISS_PDA_REL | AC-coupled RIN made by PDA_AC/PDA_DC. | Yes, from ISS | ||||||
| DC on the box | 3.3k DC | N/A | N/A | |||||
| Frontend output before HPO but after FI | PD_AMP | DC on the box | 20k DC nominal | H1:PSL-OSC_PD_AMP_DC | EPICS output visible as "FRONTEND POWER" on PSL_LASER MEDM. | No | ||
| AC on the box | 100k AC nominal | 5k HPF nominal | AMP_AC | No | ||||
| Back-propagation rejected by FI between frontend and HPO | PD_ISO | PSL monitor PD, D1002164, T100047 | DC | 750 DC nominal | H1:PSL-OSC_PD_ISO_DC | EPICS output visible as "PDISO" on PSL_LASER MEDM. | No | |
| AC | 3.75k nominal | 5k HPF nominal | ISO_AC | No | ||||
| Back-propagating HPO mode leaking from HPO cavity? | PD_INT | PSL monitor PD, D1002164, T100047 | DC | 1k? | H1:PSL-OSC_PD_INT_DC | EPICS output visible as "PDINT" on PSL_LASER MEDM. | No | |
| AC | 5k? | 5k HPF nominal | INT_AC | No | ||||
| HPO Brewster plate rejection | PD_BP | PSL monitor PD, D1002164, T100047 | DC | 1.5k nominal | H1:PSL-OSC_PD_BP_DC | EPICS output visible as "PDBP" on PSL_LASER MEDM. | No | |
| AC | 7.5k nominal | 5k HPF nominal | BP_AC | No |
I cannot edit the above entry any more, so here is an additional table showing digital filters.
(DC-coupled)
z= [0.0707, 0.0723], p= [0.3, 0.3] and 2nd order 0.3Hz Butterworth HP in addition to dewhite, DC gain of 5.
ISS inner loop (or 1st loop) diode has different filter than written above, it turns out. But 130Hz was a zero, not pole. 2.7k was a pole, not zero.
effective trans impedance = 660 Ohm (that's 0.2*3.3k).
z=[0.0707; 0.0723; 130]
p=[3.12; 3.36; 2.34k; 2.70k]
Seems like I was really, really tired, here's a correction of correction. Really sorry for the confusion.
My original table was correct.
Inner loop PD is equivalen of 660Ohm, zp=([0.0707;0.0723;2.7k],[3.12;3.36;130;2.34k]).