\documentclass{chowto}

\title{Detector Signal and High Voltage Cable Map}
\howtotype{reference} % ``expert'', ``user'', ``reference''
%\experiment{Name of experiment} % Optional
\author{H. Fenker}
\category{electronics} % Subject area of this document

%\maintainer{Name of person maintaining document} % Optional
\date{April 4, 2003}

\begin{document}
\begin{abstract}
This reference describes how to find the patch cable assignments for
signals and high voltages between the Hall-C counting house and the
detectors.

\end{abstract}

\section{Signal Cable Map}

In both the SOS and the HMS shield houses there are patch panels with
UHF style connectors. In the SOS, the patches are within the relay
racks in the electronics shack on the back of the shield house. The
HMS signal patches are located inside the shield house on the beam-left
interior wall. RG213 cable attaches each of
the patches to a set of central patch panels located in the hall
on the beam-right side of the incoming beamline. Jumpers on these
panels route the signals to a patch cable system that is connected to
panels in the counting house. Refer to Figure \ref{fig:patch_panels}
to see where the patch panels are located.

Many of these signal cables are reassigned for different experiment
configurations. Therefore, the detailed signal routing changes 
from time to time.
Such changes must be documented at the time they happen. The documentation
is maintained in a text file residing on the Hall-C file system.

For detailed patch cable information, refer to the master file 
\\ {\verb /u/group/hallc/documents/trigger/signal.map }. If you
make changes to the patch system you must update this file. When
you do so, make certain to respect the existing format of the file.
It is configured for use both as a text file and for import to 
spreadsheet and database software.

\section{Detector High Voltage Cable Map}

All of the detector Caen high voltage power supplies are located
in the counting house. High voltage is distributed to the
detectors through a system of sixteen-channel multiconductor cables
with an SHV (high voltage connector) distribution box on each end. Each
such patch box corresponds to a single sixteen-channel
Caen high voltage module. Jumpers from the Caen supplies to the
corresponding patch normally connect channels 0-0, 1-1, 2-2, ... 15-15.
In this way, at the detector end of the system, HV cables have the
same {\it mechanical} arrangement that they would (and did!) if the
Caen supply were physically present. Refer to Figure \ref{fig:patch_panels}
to see where the patch panels are located.

A text file listing the detector element assigned to each Caen
channel is automatically generated each time the HV system database
is generated after a reconfiguration. To view the detector high-voltage
assignments for the SOS high voltage system, inspect the files 
\raggedright
{\tt \$EPSHV/perl/channel\_map } and  
{\tt \$EPSHV/perl/group\_map }
 on cdaqh1
(account name cvxwrks). For the HMS system refer to the files
{\tt \$EPHHV/perl/channel\_map } and  
{\tt \$EPHHV/perl/group\_map}.
 
\begin{figure}[htp]
\begin{centering}
\includegraphics[height=0.9\textheight]{cable_map-patch_system.eps}
\caption{Locations of Main High Voltage and Signal Patch Panels
in Hall-C and the Counting Room.
\label{fig:patch_panels}}
\end{centering}
\end{figure}

\end{document}

% Revision history:
% $Log: cable_map.tex,v $
% Revision 1.1  2003/04/04 16:03:15  saw
% Initial Checkin
%
