.. auto-generated by dev_tools.docs.nxdl from the NXDL source base_classes/NXpositioner.nxdl.xml -- DO NOT EDIT .. index:: ! NXpositioner (base class) ! positioner (base class) see: positioner (base class); NXpositioner .. _NXpositioner: ============ NXpositioner ============ .. Contributors List .. |contrib_name| replace:: Aaron Brewster|phyy-nx|https://avatars.githubusercontent.com/u/13471434?v=4|2022-06-15 .. |contrib_name| replace:: Pete R Jemian|prjemian|https://avatars.githubusercontent.com/u/2279984?v=4|2022-01-28 .. |contrib_name| replace:: Peter Chang|PeterC-DLS|https://avatars.githubusercontent.com/u/1381719?v=4|2020-10-20 .. |contrib_name| replace:: Tobias Richter|zjttoefs|https://avatars.githubusercontent.com/u/856440?v=4|2018-05-15 **Status**: base class, extends :ref:`NXobject` **Description**: A generic positioner such as a motor or piezo-electric transducer. **Symbols**: No symbol table **Groups cited**: :ref:`NXtransformations` .. index:: NXtransformations (base class); used in base class **Structure**: .. _/NXpositioner@default-attribute: .. index:: default (file attribute) **@default**: (optional) :ref:`NX_CHAR ` .. collapse:: Declares which child group contains a path leading ... .. index:: plotting Declares which child group contains a path leading to a :ref:`NXdata` group. It is recommended (as of NIAC2014) to use this attribute to help define the path to the default dataset to be plotted. See https://www.nexusformat.org/2014_How_to_find_default_data.html for a summary of the discussion. .. _/NXpositioner/name-field: .. index:: name (field) **name**: (optional) :ref:`NX_CHAR ` symbolic or mnemonic name (one word) .. _/NXpositioner/description-field: .. index:: description (field) **description**: (optional) :ref:`NX_CHAR ` description of positioner .. _/NXpositioner/value-field: .. index:: value (field) **value**: (optional) :ref:`NX_NUMBER ` (Rank: 1, Dimensions: [n]) {units=\ :ref:`NX_ANY `} best known value of positioner - need [n] as may be scanned .. _/NXpositioner/raw_value-field: .. index:: raw_value (field) **raw_value**: (optional) :ref:`NX_NUMBER ` (Rank: 1, Dimensions: [n]) {units=\ :ref:`NX_ANY `} raw value of positioner - need [n] as may be scanned .. _/NXpositioner/target_value-field: .. index:: target_value (field) **target_value**: (optional) :ref:`NX_NUMBER ` (Rank: 1, Dimensions: [n]) {units=\ :ref:`NX_ANY `} targeted (commanded) value of positioner - need [n] as may be scanned .. _/NXpositioner/tolerance-field: .. index:: tolerance (field) **tolerance**: (optional) :ref:`NX_NUMBER ` (Rank: 1, Dimensions: [n]) {units=\ :ref:`NX_ANY `} maximum allowable difference between target_value and value .. _/NXpositioner/soft_limit_min-field: .. index:: soft_limit_min (field) **soft_limit_min**: (optional) :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} minimum allowed limit to set value .. _/NXpositioner/soft_limit_max-field: .. index:: soft_limit_max (field) **soft_limit_max**: (optional) :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} maximum allowed limit to set value .. _/NXpositioner/velocity-field: .. index:: velocity (field) **velocity**: (optional) :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} velocity of the positioner (distance moved per unit time) .. _/NXpositioner/acceleration_time-field: .. index:: acceleration_time (field) **acceleration_time**: (optional) :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} time to ramp the velocity up to full speed .. _/NXpositioner/controller_record-field: .. index:: controller_record (field) **controller_record**: (optional) :ref:`NX_CHAR ` Hardware device record, e.g. EPICS process variable, taco/tango ... .. _/NXpositioner/depends_on-field: .. index:: depends_on (field) **depends_on**: (optional) :ref:`NX_CHAR ` .. collapse:: NeXus positions components by applying a set of translations and rotations ... NeXus positions components by applying a set of translations and rotations to apply to the component starting from 0, 0, 0. The order of these operations is critical and forms what NeXus calls a dependency chain. The depends_on field defines the path to the top most operation of the dependency chain or the string "." if located in the origin. Usually these operations are stored in a NXtransformations group. But NeXus allows them to be stored anywhere. .. todo:: Add a definition for the reference point of a positioner. .. _/NXpositioner/TRANSFORMATIONS-group: **TRANSFORMATIONS**: (optional) :ref:`NXtransformations` .. collapse:: This is the group recommended for holding the chain of translation ... This is the group recommended for holding the chain of translation and rotation operations necessary to position the component within the instrument. The dependency chain may however traverse similar groups in other component groups. Hypertext Anchors ----------------- List of hypertext anchors for all groups, fields, attributes, and links defined in this class. * :ref:`/NXpositioner/acceleration_time-field ` * :ref:`/NXpositioner/controller_record-field ` * :ref:`/NXpositioner/depends_on-field ` * :ref:`/NXpositioner/description-field ` * :ref:`/NXpositioner/name-field ` * :ref:`/NXpositioner/raw_value-field ` * :ref:`/NXpositioner/soft_limit_max-field ` * :ref:`/NXpositioner/soft_limit_min-field ` * :ref:`/NXpositioner/target_value-field ` * :ref:`/NXpositioner/tolerance-field ` * :ref:`/NXpositioner/TRANSFORMATIONS-group ` * :ref:`/NXpositioner/value-field ` * :ref:`/NXpositioner/velocity-field ` * :ref:`/NXpositioner@default-attribute ` **NXDL Source**: https://github.com/nexusformat/definitions/blob/main/base_classes/NXpositioner.nxdl.xml