1 saw   1.1 \documentclass{chowto}
  2           
  3           \title{Operation of the Caen High Voltage System}
  4           \howtotype{user} % ``expert'', ``user'', ``reference''
  5           %\experiment{Name of experiment} % Optional
  6           \author{H. Fenker}
  7           \category{general} % Subject area of this document
  8           
  9           %\maintainer{Name of person maintaining document} % Optional
 10           \date{April 4, 2003} % Can use \today as the argument
 11           
 12           \begin{document}
 13           
 14           \begin{abstract}
 15           This manual describes how to operate the Caen High Voltage system in 
 16           Hall-C from both the front panel and from the GUI.
 17            \end{abstract}
 18           
 19           
 20           \section{Related {\it Howtos}} 
 21           The following Hall-C {\it Howto} documents may be helpful.
 22 saw   1.1 
 23           %--DELETE THOSE  DOCUMENTS MENTIONED HERE WHICH ARE IRRELEVANT
 24           User Level Documents-
 25               \par \indent \indent Monitoring SOS ``Utilities'' Systems \cite{howto:sos_detector_monitoring}
 26               \par \indent \indent Monitoring HMS ``Utilities'' Systems \cite{howto:hms_detector_monitoring}
 27               \par \indent \indent Base Equipment Checklist \cite{howto:base_equip_checklist}
 28           
 29           Expert Level Documents-
 30               \par \indent \indent Starting Up and Shutting Down the SOS Detectors \cite{howto:turn_on_sos}
 31               \par \indent \indent Starting Up and Shutting Down the HMS Detectors \cite{howto:turn_on_hms}
 32               \par \indent \indent Operating the Hall-C Flammable Gas Leak Detector System \cite{howto:flam_gas_sensors}
 33           
 34           Reference Documents-
 35               \par \indent \indent Detector Signal and High Voltage Cable Map \cite{howto:cable_map}
 36               \par \indent \indent SOS Drift Chamber High Voltage and Signal Connections \cite{howto:hms_drift_map}
 37               \par \indent \indent HMS Drift Chamber High Voltage and Signal Connections \cite{howto:sos_drift_map}
 38               \par \indent \indent SOS Nominal Settings: Voltages, Currents, Flows, etc. \cite{howto:sos_nominals}
 39               \par \indent \indent HMS Nominal Settings: Voltages, Currents, Flows, etc. \cite{howto:hms_nominals}
 40           
 41           
 42           \section{Normal HV Operation - using the Graphical User Interface}
 43 saw   1.1 \subsection{Starting the Control Screens}
 44           The detector High Voltages are set from the X terminal (hallcxt13)
 45           just to the right of the center of the main control console. This X
 46           terminal should normally be logged on to {\tt cdaqh1} with the {\tt cvxwrks}
 47           account.
 48           
 49           After logging on, control screens for the HMS and the SOS must be
 50           started. Click the left mouse button anywhere on the screen background
 51           and select the ``HMS HV'' menu item and repeat for the ``SOS HV''
 52           item. The control screens will take several seconds to start up. (If a
 53           screen fails to appear after 2 minutes, reboot vmec1 for HMS or vmec6
 54           for SOS, wait 5 minutes and try starting the screen again. If necessary,
 55           the control screens may also be started step-by-step as follows
 56           \begin{enumerate}
 57           \item {\it Open an xterm window on cdaqh1.}
 58           \item \%cd \$EPHHV {\it \{for HMS, or} \$EPSHV {\it for SOS\}}
 59           \item \%cd tk
 60           \item \%hv.tcl
 61           \item {\it After several seconds the GUI screen will be displayed.}
 62           \end{enumerate}
 63           
 64 saw   1.1 \begin{figure}[h!]
 65           \centering
 66           \includegraphics[width=\textwidth]{CAEN_HV_operation-HVGUI.eps}
 67           \caption{ A snapshot of the SOS Main High-voltage GUI Screen
 68           \label{fig:SOS_HV_GUI}}
 69           \end{figure}
 70           
 71           \subsection{Operation}
 72           The operation of the HMS and SOS HV screens is menu driven.
 73           The main GUI window includes a pair of histogram-style charts, with each
 74           bar indicating the readback voltage or current for a channel.
 75           It also provides drop-down menus and two control buttons.
 76           
 77           To turn on or modify the high voltage, use the ``Group'' menu to pull up 
 78           a control screen for the desired detector subsystem. A
 79           global ON option exists for each ``group''. (There is no ON button
 80           that turns on all the high voltage for the whole spectrometer.) Turning
 81           on the high voltage will set the voltage last stored in the Caen High
 82           Voltage mainframes. If these voltages are incorrect, they can be set
 83           with the group screens, or the restore menu item on the main screen
 84           may be used to retrieve a previous set of high voltage settings. To
 85 saw   1.1 set a new operating voltage, click the cursor in the {\tt Vset} box
 86           of the appropriate channel and change the entry to the desired setpoint.
 87           Be certain to press {\tt Enter}  while the cursor is still in the box
 88           in order to actually enter the new voltage. Similar
 89           changes may be made to the trip current (Itrip), maximum allowed voltage
 90           (Vmax), and the Ramp-Up and Ramp-Down rates (Volts per second).
 91           
 92           \subsubsection{GUI Menu Items}
 93           \begin{itemize}
 94           \item File
 95           	\begin{itemize}
 96           	\item {\bf Backup} {\it Initiates a {\tt Backup} of the current settings}
 97           	\item {\bf Restore} {\it Starts a {\tt Restore} of saved settings.}
 98           	\item {\bf Quit} {\it Terminates the GUI}
 99           	\end {itemize}
100           \item Command
101           	\begin{itemize}
102           	\item {\bf Trip RESET} {\it Resets all {\tt Tripped} channels. Use freely.}
103           	\item {\bf IDLE} {\it Stops the GUI's communication with the HV supplies}
104           	\item {\bf unIDLE} {\it Restarts the communication with power supplies}
105           	\item {\bf IDLE} beep ON/OFF {\it Start/Stop audible IDLE warning}
106 saw   1.1 	\item {\bf TRIP} beep ON/OFF {\it Start/Stop audible TRIP warning}
107           	\end{itemize}
108           \item Group
109           	\begin{itemize}
110           	\item One entry for each detector group presently defined. Select the one
111           you want to manipulate.
112           	\end{itemize}
113           \end{itemize}
114           
115           \subsubsection{GUI Buttons}
116           \begin{itemize}
117           	\item {\bf HV OFF} {\it Turn off all high voltage channels}
118           	\item {\bf Silence/Unsilence} {\it Press to silence or unsilence the audible alarm}
119           \end{itemize}
120           
121           \subsection{Monitoring the Status and Resetting Trips}
122           
123           The column labeled ``Vset'' contains the setpoint for the voltage, and
124           the column labeled ``Vmon'' contains the actual voltage as read back
125           from the power supply. The ``Imon'' column contains the current drawn
126           by the channel. The ``Status'' column shows whether the channel
127 saw   1.1 voltage is actually set or not. Occasionally a channel may trip off
128           for some reason. This is indicated by the word ``Tripped'' in the
129           Status column. To correct this, select {\bf Trip Reset} under the
130           {\bf Command} menu.
131           
132           The GUI includes a system to automatically monitor the status of all
133           channels. When not silenced, an audible alarm will sound if any of the
134           high voltage channels is found with a voltage far away from its
135           setpoint. {\bf This alarm feature should never be silenced unless an
136           operator is manually monitoring the high voltages!} The yellow button
137           on the GUI should always read {\tt Silence}, indicating that the
138           silence function has not been selected. Channels which
139           are in alarm state are listed on the bottom line of the main GUI
140           window. They are identified in the format {\tt hv\_CR\_CH}, where {\tt
141           CR} is the Caen crate number and {\tt CH} is the high voltage channel
142           number. If necessary to identify the bad channel(s), you can refer to
143           the automatically generated high voltage map files {\tt
144           \$EPHHV/perl/channel\_map} and {\tt \$EPSHV/perl/channel\_map}
145           discussed in references \cite{howto:cable_map}.
146           
147           \subsection{Backup and Restore}
148 saw   1.1 If permanent changes are made to the high voltages, these new settings
149           should be saved with the {\bf Backup} menu item. Similarly, you can
150           {\bf Restore} setpoints that have previously been backed up.  Note:
151           Backup and restore operations take an extremely long time (several
152           minutes).
153           
154           
155           \section{Caen Power Supply Operation from the Front Panel}
156           
157           Modifications to the parameter settings should in general not be made
158           at the front panel or through a locally connected terminal if the
159           EPICS system is in operation. This mode of control is meant for
160           diagnostics and testing of a detector system prior to running. There
161           are only two features which must be set at the front panel before
162           initiating an EPICS control session - the crate number and the
163           RS232 configuration (suggested
164           defaults are 9600 baud, no parity, 1 stop bit).
165           
166           If unfamiliar with the operation of the HV system in local mode, one
167           should get experienced personnel or review  Chapter 4 of the
168           Caen Technical Information Manual \cite{howto:CAEN_HV_TechMan}.
169 saw   1.1 Operation is generally straightforward, however. Use the arrow
170           and menu buttons to get the desired channel on the LCD display,
171           then use the arrow buttons to select the parameter you wish to
172           change. Use the {\tt Modify} and {\tt Change} menu items to initiate
173           the change; use arrows or numeric keypad to set the new value.
174           To turn a channel {\tt ON}, for example, display the channel, 
175           move the cursor over the word {\tt OFF}, and press {\tt MODIFY}.
176           
177           \section{Outside Influences}
178           Each Caen mainframe has an {\it Interlock} input on the front
179           panel which may be used to disable high voltage output unless desired
180           external conditions are satisfied. For example, if the gas
181           system is in alarm the wire chamber high voltage will be shut off.
182           Because they share a common crate, the high voltage supplies for
183           both the HMS Gas \v{C} erenkov counter and the HMS drift chambers
184           will be disabled. If you discover that you cannot get certain high
185           voltage channels to come up, try to find out if they are interlocked.
186           
187           \end{document}
188           
189           % Revision history:
190 saw   1.1 % $Log$