3.3.1.29. NXlog

Status:

base class, extends NXobject, version 1.0

Description:

Information recorded as a function of time.

Description of information that is recorded against time, such as information monitored during the run. It contains the logged values and the times at which they were measured as elapsed time since a starting time recorded in ISO8601 format. This method of storing logged data helps to distinguish instances in which a variable is a dimension scale of the data, in which case it is stored in an NXdata group, and instances in which it is logged during the run, when it should be stored in an NXlog group. Note: When using multiple NXlog groups, it is suggested to place them inside a NXcollection group. In such cases, when NXlog is used in another class, NXcollection/NXlog is then constructed.

Symbols:

No symbol table

Groups cited:

none

Structure:

time: NX_FLOAT {units=NX_TIME}

Time of logged entry. The times are relative to the “start” attribute and in the units specified in the “units” attribute.

@start: NX_DATE_TIME

value: NX_NUMBER {units=NX_ANY}

Array of logged value, such as temperature

raw_value: NX_NUMBER {units=NX_ANY}

Array of raw information, such as thermocouple voltage

description: NX_CHAR

Description of logged value

average_value: NX_FLOAT {units=NX_ANY}

average_value_error: NX_FLOAT {units=NX_ANY}

estimated uncertainty (often used: standard deviation) of average_value

minimum_value: NX_FLOAT {units=NX_ANY}

maximum_value: NX_FLOAT {units=NX_ANY}

duration: NX_FLOAT {units=NX_ANY}

Total time log was taken

NXDL Source:

https://github.com/nexusformat/definitions/blob/master/base_classes/NXlog.nxdl.xml