.. auto-generated by script ../../../../utils/nxdl2rst.py from the NXDL source NXpositioner.nxdl.xml

.. index::
    ! NXpositioner (base class)
    ! positioner (base class)
    see: positioner (base class); NXpositioner

.. _NXpositioner:

============
NXpositioner
============

**Status**:

  base class, extends :ref:`NXobject`, version 1.0

**Description**:

  A generic positioner such as a motor or piezo-electric transducer.

  It is used to document the
  current information of a piece of beam line equipment.
  Note: When using multiple :ref:`NXpositioner` groups, it is suggested to place 
  them inside a :ref:`NXcollection` group.  In such cases, when
  :ref:`NXpositioner` is used in another class,
  :ref:`NXcollection`/:ref:`NXpositioner` 
  is then constructed.

**Symbols**:

  No symbol table

**Groups cited**:
  none

**Structure**:

  .. index:: name (field)

  **name**: :ref:`NX_CHAR <NX_CHAR>`

    symbolic or mnemonic name (one word)

  .. index:: description (field)

  **description**: :ref:`NX_CHAR <NX_CHAR>`

    description of positioner

  .. index:: value (field)

  **value[n]**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    best known value of positioner - need [n] as may be scanned

  .. index:: raw value (field)

  **raw_value[n]**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    raw value of positioner - need [n] as may be scanned

  .. index:: target value (field)

  **target_value[n]**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    targeted (commanded) value of positioner - need [n] as may be scanned

  .. index:: tolerance (field)

  **tolerance[n]**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    maximum allowable difference between target_value and value

  .. index:: soft limit min (field)

  **soft_limit_min**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    minimum allowed limit to set value

  .. index:: soft limit max (field)

  **soft_limit_max**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    maximum allowed limit to set value

  .. index:: velocity (field)

  **velocity**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    velocity of the positioner (distance moved per unit time)

  .. index:: acceleration time (field)

  **acceleration_time**: :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    time to ramp the velocity up to full speed

  .. index:: controller record (field)

  **controller_record**: :ref:`NX_CHAR <NX_CHAR>`

    Hardware device record, e.g. EPICS process variable, taco/tango ...

**NXDL Source**:
  https://github.com/nexusformat/definitions/blob/master/base_classes/NXpositioner.nxdl.xml