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:
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. |