Add caching docs

docs/ADAravis/ADAravis.rst

@@ -21,25 +21,25 @@ Overview
 
 This is an :doc:`../index` driver for GenICam_ cameras using the aravis_ library.
 
-GenICam_ is a Generic Interface for Cameras from the European Machine Vision Association (EMVA). 
+GenICam_ is a Generic Interface for Cameras from the European Machine Vision Association (EMVA).
 
 ADAravis is derived from the base class ADGenICam_, which handles many of the details of
 mapping GenICam_ features to EPICS records.
 
 `ADAravis class`_ describes this class in detail.
 
-ADAravis_ is based heavily on the older aravisGigE_ driver which has been part of areaDetector for many years.  
+ADAravis_ is based heavily on the older aravisGigE_ driver which has been part of areaDetector for many years.
 ADAravis_ differs from aravisGigE_ by using the ADGenICam_ base class to significantly reduce the amount of code.
 Many of the ideas in ADGenICam_ were borrowed from aravisGigE_.
 
 As its name implies, ADAravis_ uses the aravis_ library.  It runs on most Linux systems, and can control any GenICam_ camera.
 It cannot be used on Windows because aravis_ does not support it.
 
-The aravis_ package must be built before building ADAravis.  Instructions for doing this can be found in the 
+The aravis_ package must be built before building ADAravis.  Instructions for doing this can be found in the
 :ref:`ADGenICam installing aravis <ADGenICam_installing_aravis>` documentation.
 
-Prior to using ADAravis with a specific camera model, the XML file must be read from the camera using the arv-tool utility, 
-and the EPICS database file and OPI screens must be generated by running the Python programs in 
+Prior to using ADAravis with a specific camera model, the XML file must be read from the camera using the arv-tool utility,
+and the EPICS database file and OPI screens must be generated by running the Python programs in
 :ref:`ADGenICam Python scripts <ADGenICam_Python_scripts>`.
 
 
@@ -123,14 +123,16 @@ IOC startup script
 ------------------
 The command to configure an ADAravis camera in the startup script is::
 
-  aravisConfig(const char *portName, const char *cameraName, size_t maxMemory, int priority, int stackSize)
-
+  aravisConfig(const char *portName, const char *cameraName, int enableCaching, size_t maxMemory, int priority, int stackSize)
 ``portName`` is the name for the ADAravis port driver
 
 ``cameraName`` is the identifier for the camera.  It can be the complete camera name returned by arv-tool, for example
 ``"Point Grey Research-Blackfly S BFS-PGE-50S5C-18585624"``, or it can be an IP address for GigE and 10 GigE cameras, for
 example ``"164.54.160.117"``.
 
+``enableCaching`` Flag to enable (1) or disable (0) register caching in aravis. Performance is much better when caching is
+enabled, but some cameras may not properly implement this.
+
 ``maxMemory`` is the maximum amount of memory the NDArrayPool is allowed to allocate.  0 means unlimited.
 
 ``priority`` is the priority of the port thread.  0 means medium priority.
@@ -140,10 +142,10 @@ example ``"164.54.160.117"``.
 MEDM screens
 ------------
 The following is the MEDM screen ADAravis.adl when controlling a FLIR Oryx 51S5M 10 Gbit Ethernet camera.
-ADAravis.adl is very similar to ADGenICam.adl, with a few additional widgets for the PVs that are 
+ADAravis.adl is very similar to ADGenICam.adl, with a few additional widgets for the PVs that are
 specific to ADAravis.
 
-Note that each frame is 4.8 MB, and it is collecting 162 frames/s, which is 775 MB/s. 
+Note that each frame is 4.8 MB, and it is collecting 162 frames/s, which is 775 MB/s.
 
 .. figure:: ADAravis.png
     :align: center
@@ -159,4 +161,3 @@ The following is the second feature screen generated by the Python program descr
 
 .. figure:: ADAravis_features2.png
     :align: center
-