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doc/programmer/o2t.tex

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+\subsection{Omega 2Theta}
+This is an example for a simple virtual motor. It uses two motors and runs
+the second one to exactly the double value of the first one. It can be used
+to implement omega--two--theta (o2t) scans at reflectometers of four circle
+diffractometers using the normal scan command.
+
+The o2t module uses the following data structure:
+\begin{verbatim}
+  typedef struct __SicsO2T {
+                            pObjectDescriptor pDes;
+                            pIDrivable pDrivInt;
+                            pMotor pOmega;
+                            pMotor pTheta;
+                            } SicsO2T;
+
+\end{verbatim}
+The fields:
+\begin{description}
+\item[pDes] A pointer to the usual SICS object descriptor.
+\item[pDrivInt] A pointer to the drivable interface implemented by this
+variable.
+\item[pOmega] A pointer to the first motor to use.
+\item[pTheta] A pointer to the motor data structure of the second (double)
+motor to use.
+\end{description}
+
+
+Most of this modules action lives in the drivable interface. The rest is
+achieved through the following functions:
+\begin{description}
+\item[pSicsO2T MakeO2T(char *omega, char *theta, SicsInterp *pSics)] creates
+a new o2t object from motors omega and theta. Returns NULL on failure and  a
+pointer to an o2t data structure on success.
+\item[void DeleteO2T(void *pData)] deletes an o2t object.
+\item[int CreateO2T(SConnection *pCon, SicsInterp *pSics, void *pData,\\
+                int argc, char *argv[])] The object factory function for o2t
+objects.
+\end{description}
+
+Please note, that o2t is just a helper variable and can not be manipualted
+from the SICS interpreter.
+