Standalone HV Control

For the time being, the HV control software is independent of the pot
control software. This will be fixed in a future version but for the
meantime, use the following steps to control the HV to the castles.

1.  From d0ol13 in the SCR, type

    a.  setup onl_apps

    b.  hv_crate.py /online/config/fpd/hv/fpd.hvc &

2.  This will open the HV gui from which we can control the voltage to
    the L0 PMTs and the MAPMTs.

3.  On the left is a list of what we can turn on.

    a.  At the top are the L0 PMTs for the castles. We can only control
        L0 at the castle level so when we turn these on, we are
        supplying HV to all L0 tubes in the castle (up to 4 detectors).
        These are PMTP1 (P1 castle), PMTP2 (P2 castle), PMTA1 (A1
        castle), PMTA2 (A2 castle) and PMTDI (both D1 and D2). This will
        provide the same voltage to all L0 PMTs at that location.

    b.  After this we can control each location of the MAPMTs separately
        so we have MAP1U, MAP1D, MAP2I, MAP2O and similar for P2, A1 and
        A2 as well as MADI1 and MADI2. This will provide the same
        voltage to all 7 MAPMTs at that location.

4.  On the right of the list is the control button. When the program is
    first turned on, this should be off (blue) for all tubes.

5.  First, choose which L0 tubes you want to turn on by clicking on the
    right button. (DO NOT turn on any MAPMTs until you have verified
    rates from the L0 tubes) This will give you a drop down list from
    which you select on. This should turn the button orange.

6.  Next set the voltage to which you want to go. This can be done in
    two ways.

    a.  Click on SET_HV. This will open a drop down menu from which you
        can select a percentage value of the maximum allowed voltage
        (currently -1700V). All channels that you have turned on will be
        set to this value.

    b.  You can also set a different voltage for each channel. To do
        this, click on the V_set box for the channel of interest and
        type in the value of the voltage you want (this should be a
        negative value with magnitude less than or equal to 1700V). Hit
        enter for the value to be accepted.

7.  When the voltages are set, click on the ramp button. This will ramp
    the voltages on the tubes up to the desired level. Currently the
    ramping happens very quickly so it might be preferable to manually
    select different voltages until you reach the desired voltage. The
    control button will turn yellow and read average or ramp then it
    will turn green and be labeled holding when the desired voltage is
    reached. If too much current or too much voltage is being drawn, the
    button will turn red. If you press the reset button, this will take
    the voltage back down to zero. This probably means there is
    something wrong with the tube in that location.

    a.  Verify that the V_read value is near the V_set value.

    b.  Verify that the number of tubes you expect to be drawing current
        is actually the case by looking at I_read. Each tube in that
        channel should draw the same amount of current (this will
        increase with increased voltage). Compare with other channels
        with the same number of tubes that you have turned on. If you
        notice a discrepancy (i.e. one of the channels is not drawing as
        much current as another channel with the same number of tubes at
        the same voltage) there is a problem with a L0 tube in that
        location. You can look at the signals from that location to
        determine which tube it is.

8.  When the tubes are operating at the desired voltage, press the
    control button and choose locked from the drop down menu. This will
    prevent the voltage from being accidently changed.

9.  Verify the rates from the L0 tubes. If safe, you can now repeat this
    procedure for the MAPMTs you want to turn on. Do not turn on any
    MAPMTs until you have verified the rate from its associated L0 tube.

10. When finished collecting data, you can follow a similar procedure to
    turn of the voltage. It is VERY IMPORTANT that you ramp the voltage
    down slowly. The program is supposed to ramp the voltage down but
    until we are sure, use several voltage steps while ramping down the
    voltage. Don't turn off the voltage until the tubes are back in the
    home position or we will be unable to monitor rates while the tubes
    are moving.

11. Once the tubes are at 0 voltage, turn them off again from the
    control drop down for each channel. Before you leave all channels
    should have blue buttons on the right that read OFF.