NXpositioner¶
Status:
base class, extends NXobject
Description:
A generic positioner such as a motor or piezo-electric transducer.
Symbols:
No symbol table
- Groups cited:
Structure:
@default: (optional) NX_CHAR
Declares which child group contains a path leading to a 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.
name: (optional) NX_CHAR
symbolic or mnemonic name (one word)
description: (optional) NX_CHAR
description of positioner
value: (optional) NX_NUMBER (Rank: 1, Dimensions: [n]) {units=NX_ANY}
best known value of positioner - need [n] as may be scanned
raw_value: (optional) NX_NUMBER (Rank: 1, Dimensions: [n]) {units=NX_ANY}
raw value of positioner - need [n] as may be scanned
target_value: (optional) NX_NUMBER (Rank: 1, Dimensions: [n]) {units=NX_ANY}
targeted (commanded) value of positioner - need [n] as may be scanned
tolerance: (optional) NX_NUMBER (Rank: 1, Dimensions: [n]) {units=NX_ANY}
maximum allowable difference between target_value and value
soft_limit_min: (optional) NX_NUMBER {units=NX_ANY}
minimum allowed limit to set value
soft_limit_max: (optional) NX_NUMBER {units=NX_ANY}
maximum allowed limit to set value
velocity: (optional) NX_NUMBER {units=NX_ANY}
velocity of the positioner (distance moved per unit time)
acceleration_time: (optional) NX_NUMBER {units=NX_ANY}
time to ramp the velocity up to full speed
controller_record: (optional) NX_CHAR
Hardware device record, e.g. EPICS process variable, taco/tango …
depends_on: (optional) NX_CHAR
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.
TRANSFORMATIONS: (optional) NXtransformations
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.
