Normal HV Operation - using the Graphical User Interface

Starting the Control Screen

The detector High Voltages can be set from any counting house workstation logged into the cvxwrks account. Typically, the workstation at the right end of the console (jeffylab) or the workstation on the shelf on the left end of the console (cdaql5) as the CPUs are located next to the monitors allowing alarms to be heard.

To start the HV Control GUI, pop up an terminal window on a counting house workstation that is logged into the cvxwrks account. If you want to run from a screen that is not logged on as cvxwrks, or a machine that is not a counting house workstation, then connect with ssh cvxwrks@cdaql4. Then follow this procedure:

1. %cd $EPHKSHV/tk
2. %./hv.tcl
3. After several seconds the GUI screen will be displayed.

If nothing happens for a while, and then hv.tcl terminates with some error messages, reboot g0ioc3, the EPICS IOC used to communicate with the CAEN power supplies.

Figure 1: A snapshot of the SOS Main High-voltage GUI Screen

Operation

The operation of the HKS HV screens is menu driven. The main GUI window includes a pair of histogram-style charts, with each bar indicating the readback voltage or current for a channel. It also provides drop-down menus and two control buttons.

To turn on or modify the high voltage, use the ``Group'' menu to pull up a control screen for the desired detector subsystem. A global ON option exists for each ``group''. (There is no ON button that turns on all the high voltage for the whole spectrometer.) Turning on the high voltage will set the voltage last stored in the Caen High Voltage mainframes. If these voltages are incorrect, they can be set with the group screens, or the restore menu item on the main screen may be used to retrieve a previous set of high voltage settings. To set a new operating voltage, click the cursor in the Vset box of the appropriate channel and change the entry to the desired setpoint. Be certain to press Enter while the cursor is still in the box in order to actually enter the new voltage. Similar changes may be made to the trip current (Itrip), maximum allowed voltage (Vmax), and the Ramp-Up and Ramp-Down rates (Volts per second).

GUI Menu Items

• File
  • Backup Initiates a Backup of the current settings
  • Restore Starts a Restore of saved settings.
  • Quit Terminates the GUI
• Command
  • Trip RESET Resets all Tripped channels. Use freely.
  • IDLE Stops the GUI's communication with the HV supplies
  • unIDLE Restarts the communication with power supplies
  • IDLE beep ON/OFF Start/Stop audible IDLE warning
  • TRIP beep ON/OFF Start/Stop audible TRIP warning
• Group
  • One entry for each detector group presently defined. Select the one you want to manipulate.

GUI Buttons

• HV OFF Turn off all high voltage channels
• Silence/Unsilence Press to silence or unsilence the audible alarm

Monitoring the Status and Resetting Trips

The column labeled ``Vset'' contains the setpoint for the voltage, and the column labeled ``Vmon'' contains the actual voltage as read back from the power supply. The ``Imon'' column contains the current drawn by the channel. The ``Status'' column shows whether the channel voltage is actually set or not. Occasionally a channel may trip off for some reason. This is indicated by the word ``Tripped'' in the Status column. To correct this, select Trip Reset under the Command menu.

The GUI includes a system to automatically monitor the status of all channels. When not silenced, an audible alarm will sound if any of the high voltage channels is found with a voltage far away from its setpoint. This alarm feature should never be silenced unless an operator is manually monitoring the high voltages! The yellow button on the GUI should always read Silence, indicating that the silence function has not been selected. Channels which are in alarm state are listed on the bottom line of the main GUI window. They are identified in the format hv_CR_CH, where CR is the Caen crate number and CH is the high voltage channel number. If necessary to identify the bad channel(s), you can refer to the automatically generated high voltage map file $EPHKSHV/perl/channel_map discussed in references [].

Backup and Restore

If permanent changes are made to the high voltages, these new settings should be saved with the Backup menu item. Similarly, you can Restore setpoints that have previously been backed up. Note: Backup and restore operations take an extremely long time (several minutes).