niHWS_NewWfmReference

NI-HWS C Function Reference

niHWS_NewWfmReference

C Function Prototype

tHWS_Status niHWS_NewWfmReference (tHWS_FileHandle fileHandle, const char groupName[], const char wfmName[], long compressionLevel, tHWS_WfmRef* wfmReference);

Purpose

Creates a new waveform in the specified group and returns a reference to it.

Waveforms are identified by reference for purposes of setting and getting waveform attributes and reading and writing data.

Parameters

Name Type Description
fileHandle tHWS_FileHandle Refers to an open HWS file.
groupName const char[] Identifies the group that the new waveform is created in.

If the group referred to by the groupName parameter does not exist, then a new group is created and given the name assigned to groupName.

groupName can be NULL or the empty string under the following conditions:

  1. The file is new and without groups. A new group is created, and the new waveform is created in that group.
  2. Only one group is in the file. The new waveform is created in that group.
wfmName const char[] The name of the waveform. If this waveform is the only one in the group, then the name is optional (it can be NULL or the empty string). Otherwise, you must supply a name when creating a new waveform.
compressionLevel long Provides control over the amount of compression applied to the waveform samples as they are written to the HWS file.

A value of 0 means no compression. A value of 9 means maximum compression. Values between zero and nine indicate increasing levels of compression.

wfmReference tHWS_WfmRef* References the waveform. Waveforms are identified by reference for purposes of setting and getting waveform attributes and for reading and writing data.

Return Value