\subsection{Slit Motor}

\textbf{slit\_type field} - This integer field select the type of slit
pseudomotor that this record represents.  There are four possible values
for the \textit{slit\_type} field, which come in two groups of two, namely,
the SAME case and the OPPOSITE case.  The allowed values are:
\begin{itemize}
  \item 1 - \textit{(MXF\_SLIT\_CENTER\_SAME)}
  \item 2 - \textit{(MXF\_SLIT\_WIDTH\_SAME)}
  \item 3 - \textit{(MXF\_SLIT\_CENTER\_OPPOSITE)}
  \item 4 - \textit{(MXF\_SLIT\_WIDTH\_OPPOSITE)}
\end{itemize}

The SAME cases above are for slit blade pairs that move in the same
physical direction when they are both commanded to perform moves of
the same sign.  The OPPOSITE cases are for slit blade pairs that move
in the opposite direction from each other when they are both commanded
to perform moves of the same sign.

As an example, for a top and bottom slit blade pair, if a positive
move of each causes both blades to go up, you use the SAME case.
On the other hand, if a positive move of each causes the top slit
blade to go up and the bottom slit blade to go down, you use the
OPPOSITE case.

