LAT00x - Power On

Notes

• The following is from Jana answering some of my questions:

  • • • What does "current delta is in range" mean?
        Current delta is defined as the difference between a BPU current measured before a unit is turned on and after a unit is turned on.
        For example, before the SIU is turned on, the BPU SIU feed will register 0.1A (don't ask why it's not zero). After the SIU is turned on, it will read 0.7A. The current delta for turning the SIU on is 0.6A.
        You can do the same for the DAQ feed for the PDU and GASU.

  • • • How to issue LMAINFEEDON command?
        You should be able to issue the LMAINFEEDON command more than once (can you?) and you should be able to turn on primary GASU first followed by PDU0. These will be separate calls to LMAINFEEDON and you should read the BPU current on the DAQ feed before and after you turn each on and see that the difference is appropriate.
        Yes, PDU on is a separate command (to LMAINFEEDON)
        GASU on is also a separate command.

  • • • Don't worry about LTC_init for now. LTC is undergoing some changes, so it doesn't pay to worry about it.

  • • • What are the CAL and TKR bias voltages supposed to be set to upon power up? Should they be the same as the current values in the clean room? What is their nominal value?
        Looks like Rich gave you an answer to that.

  • • • Testbed doesn't model CAL Baseplate temperatures. Why not?
      • Testbed doesn't seem return valid values for TKR T1
        I'm hoping you have an answer from Owen on these?

  • • • Does the ACDPowerOn Command enable the converters inside the GASU?
        Yes, it should.
        If so, why is there a separate step for enabling the converters?
        That's Rich's mistake. Just use ACDPowerOn.

  • • • What is the nominal value for the bias voltage for the ACD?
        No clue

  • • • What are the proper ranges for all of these values?
        Systems will provide, but they haven't yet.

• Jana's later e-mail regarding MAINFEEDON:

  So, I talked to James about how the MAINFEEDON was intended to be used by FSW. He maintains that it was only meant to be issued once, and that issuing it a second time might make LIM complain. In addition, he and Mike talked through the power-up sequence (with regard to the PDU and GASU) a long time ago and they decided that there was no additional information to be gained by turning them on separately. FSW's intention was to turn PDU and GASU on simultaneously.
  I asked Selim to implement the power on sequence in that way: PDU and GASU on simultaneously. If anyone still has cold feet about turning these two things on at once, please let me know.

• On the testbed EPU 3.3V voltage (LHKPxEPUy33V)is reporting 2.25V instead of 3.3V.
• On the testbed unless I turn on the power to ACD free board 0 the status for all the free board temperatures report not ready. Also the temperatures are all reporting as -114.72C. Does that mean that no thermistor cables are attached to the ACD? Got this response from Jana:

  I'm not sure how the testbed models the ACD environmental quantities and loads, so I have no idea whether to worry about the not ready status. At any rate, we should just record this as another testbed "feature".
  The temperatures that are reading back -114.72C are probably reading back 0 counts (or something less than ~5 counts) which is consistent with the thermistor circuit not having power or an open circuit (no cable attached). You can check if this -114.72 is consistent with 0 by looking at the raw data coming back, before EGUs are applied.

• On the testbed, only for TEM 10, I am getting an out-of-bounds value for TKR C0 T0. If you look at payload mnemonic LHKTATKRC0T0 below you will see that it has a value of 0xfb5 which is 4021. The thermistor counts only go up to 4015.
• On the testbed the CAL AFEE temperatures for TEM 4 are showing incorrect measurements. See the report here testLatInit_101199316.html
• On the testbed the ACD BEA grid temperatures and PMT rail temperatures report invalid values.

Questions

• It is not clear what the test script should do if one of the prerequisite/verification tests fails. Should it immediately abort the test or should it run all the prerequisite/verification steps and if at least one of them failed then abort the test?
• Another uncertainty is where we need to set the SIU/DAQ paths (cross-strapping). That is where do we need to call vsc.siuSelect(...) and vsc.daqSelect(...) which sets the AA, AB,... etc. redundant or primary paths? Should this come from some sort of schema/configuration file?
• Right now for the testbed SIU feed voltage, DAQ feed voltage and current delta requires the manual task of checking these measurements by looking at the panel, are these going to be provided as telemetry eventually?
• Rich Bialewski indicates that the logical SIU unit id is always 0. Is this accurate?
• When checking SIU and EPU boot telemetry we verify that we are in boot code mode (BOOT_MODE_COMMAND) is this accurate?
• Do we test VCHP functionality on the ground (see SIU Control of TCS in the LAT start up document)? If so how?
• Steps 8 and 10 of the LAT start up document have this as a verification test: EPU-x HK telemetry is present. How do we get this telemetry?