Add NDPluginPvxs docs

Author: jsouter

docs/ADCore/NDPluginPvxs.rst

@@ -0,0 +1,66 @@
+NDPluginPvxs
+===========
+:author: James Souter, Diamond Light Source
+
+.. contents:: Contents
+
+Overview
+--------
+
+This plugin reimplements the functionality of :ref:`NDPluginPva`, but requires the linking
+of the pvxs support module, with no requirement for the pvAccessCPP, pvDatabaseCPP, pvDataCPP or
+normativeTypesCPP support modules. The plugin wraps a pvxs SharedPV, which is added to
+the singleton PVXS server that is started when the IOC starts. 
+
+NDPluginPvxs defines the following parameters.
+
+.. cssclass:: table-bordered table-striped table-hover
+.. flat-table::
+  :header-rows: 2
+  :widths: 5 5 5 70 5 5 5
+
+  * -
+    -
+    - **Parameter Definitions in NDPluginPvxs.h and EPICS Record Definitions in NDPvxs.template**
+  * - Parameter index variable
+    - asyn interface
+    - Access
+    - Description
+    - drvInfo string
+    - EPICS record name
+    - EPICS record type
+  * - NDPluginPvxsPvName
+    - asynOctet
+    - r/o
+    - Name of the EPICSv4 PV being served
+    - PV_NAME
+    - $(P)$(R)PvName_RBV
+    - waveform
+
+
+Configuration
+-------------
+
+The NDPluginPvxs plugin is created with the ``NDPvxsConfigure`` command,
+either from C/C++ or from the EPICS IOC shell.
+
+::
+
+   NDPvxsConfigure (const char *portName, int queueSize, int blockingCallbacks,
+                         const char *NDArrayPort, int NDArrayAddr, const char *pvName,
+                         size_t maxMemory, int priority, int stackSize)
+     
+
+For details on the meaning of the parameters to this function refer to
+the detailed documentation on the NDPvxsConfigure function in the
+`NDPluginPvxs.cpp
+documentation <../areaDetectorDoxygenHTML/_n_d_plugin_pvxs_8cpp.html>`__ and
+in the documentation for the constructor for the `NDPluginPvxs
+class <../areaDetectorDoxygenHTML/class_n_d_plugin_pvxs.html>`__.
+
+Starting the pvxs server
+----------------------------
+
+Unlike NDPluginPva, the EPICSv4 PV will be automatically served in an IOC if the plugin
+is configured, however the 
+`IOC must be built with pvxsIoc.dbd and the pvxs and pvxsIoc libraries. <https://epics-base.github.io/pvxs/building.html#including-pvxs-in-your-application>`