niHWS_RetrieveDigitalWfmU32

NI-HWS C Function Reference

niHWS_RetrieveDigitalWfmU32

C Function Prototype

tHWS_Status niHWS_RetrieveDigitalWfmU32 (const char filePath[], double* rate, long validSignalsSize, char validSignals[], long wfmBufferSize, unsigned long* wfmBuffer, long* numSamplesInWfm);

Purpose

Retrieves the digital waveform samples as 32-bit unsigned integers (U32) from the file specified.

Parameters

Name Type Description
filePath const char[] Specifies the path and filename of the HWS file to create or open. The .hws extension is typically used for HWS files, although using this extension is optional.
rate double* The rate of the Sample clock used to capture the waveform.
validSignalsSize long The number of characters that the string allocated for the validSignals parameter can hold.

If validSignalsSize is 0 and no error occurs, the actual size of the validSignals string, including the end of string termination character, is returned in the status parameter.

validSignals char[] The list of lines (or bits) in the digital samples that are valid. For example, "0,3,6" means that only bits 0, 3, and 6 of each unsigned long digital sample contain valid digital data.

The values in the string can receive any integer value between 0 and 31. Individual lines are separated by commas. You can use a hyphen to denote an inclusive range of lines. For example, "2-5" is equivalent to "2,3,4,5".

wfmBufferSize long Specifies how many samples to read into wfmBuffer.

If wfmBufferSize is 0, the number of samples in the waveform is returned in numSamplesInWfm.

wfmBuffer unsigned long* Contains the data for the waveform. This array must be large enough to contain at least the amount of data indicated by the value assigned to wfmBufferSize.
numSamplesInWfm long* Reports the total number of samples in the waveform.

Return Value