niHSDIO_ConfigurePatternMatchRefTrigger

NI Digital Waveform Generator/Analyzer

niHSDIO_ConfigurePatternMatchRefTrigger

Specific Function

C Function Prototype

ViStatus niHSDIO_ConfigurePatternMatchRefTrigger (ViSession vi, ViConstString channelList, ViConstString pattern, ViInt32 triggerWhen, ViInt32 pretriggerSamples);

Purpose

Configures the Reference trigger for pattern-match triggering. If the Reference trigger asserts before all the pretrigger samples are acquired, then it is ignored. This function is only valid for acquisition sessions.

Valid Syntax:
Both of the following examples are valid and do the same thing. The order of channelList determines the order of the pattern string.

  • niHSDIO_ConfigurePatternMatchAdvanceTrigger (vi, "19-0", "0000 0XXX XX11 1111 1111");
  • niHSDIO_ConfigurePatternMatchAdvanceTrigger (vi, "0-19", "1111 1111 11XX XXX0 0000");
Note  The logic levels seen by pattern matching are affected by data interpretation.

Parameters

Name Type Description
vi ViSession This handle identifies your instrument session. vi was obtained from niHSDIO_InitAcquisitionSession.
channelList ViConstString This string specifies which channels are configured for pattern matching using the pattern string. The order of channels in the list determines the order of the pattern string.
pattern ViConstString This string expression describes the pattern to be matched. This expression is composed of the following characters:
  • X or x: Ignore the channel
  • 1: Match on a logic 1
  • 0: Match on a logic 0
  • R or r: Match on a rising edge
  • F or f: Match on a falling edge
  • E or e: Match on either edge

The first character in the expression corresponds to the first channel in channelList. The number of characters in pattern must correspond to the number of channels specified in channelList, or an error is returned.

triggerWhen ViInt32 Specifies when the trigger asserts.

Defined Values

NIHSDIO_VAL_PATTERN_MATCHES (36)—The trigger asserts when the pattern matches.
NIHSDIO_VAL_PATTERN_DOES_NOT_MATCH (37)—The trigger asserts when the pattern does not match.

Default Value: NIHSDIO_VAL_PATTERN_MATCHES
pretriggerSamples ViInt32 Specifies the number of necessary pretrigger samples before the Reference trigger is acknowledged.

Return Value