Table Of Contents

Configure Trigger (Analog » Video) (G Dataflow)

Last Modified: April 2, 2018

Configures the common properties specific to video triggering.

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TV event

The TV event to trigger on.

Name Value Description
Field 1 1 Triggers on field 1 of the signal.
Field 2 2 Triggers on field 2 of the signal.
Any Field 3 Triggers on any field of the signal.
Any Line 4 Triggers on the first line acquired.
Line Number 5 Triggers on a specific line of a video signal. Valid values vary depending on the signal format.
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trigger coupling

The method used to couple the trigger signal.

Name Value Description
AC 0 Couples the trigger signal with an AC current.
DC 1 Couples the trigger signal with a DC current.
HF Reject 3 Couples the trigger signal with a high frequency reject filter.
LF Reject 4 Couples the trigger signal with a low frequency reject filter.
AC Plus HF Reject 1001 Couples the trigger signal with an AC current and a high frequency reject filter.

Default: DC

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polarity

The polarity of the video sync.

Name Value Description
Positive 1 Syncs the video with positive polarity.
Negative 2 Syncs the video with negative polarity.
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session in

Handle that identifies the NI-SCOPE instrument session as previously allocated by Initialize With Options.

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error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

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trigger source

The source you want the digitizer to monitor for a trigger.

Name Description
Channel 0 Monitors Channel 0 for a trigger signal.
Channel 1 Monitors Channel 1 for a trigger signal.
Channel 2 Monitors Channel 2 for a trigger signal.
Channel 3 Monitors Channel 3 for a trigger signal.
Channel 4 Monitors Channel 4 for a trigger signal.
Channel 5 Monitors Channel 5 for a trigger signal.
Channel 6 Monitors Channel 6 for a trigger signal.
Channel 7 Monitors Channel 7 for a trigger signal.
External TRIG Monitors an external trigger input for a trigger signal.

Default: Channel 0

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enable DC restore

Offsets each video line so the clamping level (the portion of the video line between the color burst and the beginning of the active image) is moved to zero volts.

True Sets the clamping level to zero volts.
False Keeps the clamping level at its default value.
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signal format

The video format to use.

Name Value Description
M-NTSC 1 Uses the M-NTSC video format for the video trigger.
B/G-PAL 2 Uses the B/G-PAL video format for the video trigger.
SECAM 3 Uses the SECAM video format for the video trigger.
M-PAL 1001 Uses the M-PAL video format for the video trigger.
480i/59.94 fps 1010 Uses the 480i video format at 59.94 frames per second for the video trigger.
480i/60 fps 1011 Uses the 480i video format at 60 frames per second for the video trigger.
480p/59.94 fps 1015 Uses the 480p video format at 59.94 frames per second for the video trigger.
480p/60 fps 1016 Uses the 480p video format at 60 frames per second for the video trigger.
576i/50 fps 1020 Uses the 576i video format at 50 frames per second for the video trigger.
576p/50 fps 1025 Uses the 576p video format at 50 frames per second for the video trigger.
720p/50 fps 1031 Uses the 720p video format at 50 frames per second for the video trigger.
720p/59.94 fps 1032 Uses the 720p video format at 59.94 frames per second for the video trigger.
720p/60 fps 1033 Uses the 720p video format at 60 frames per second for the video trigger.
1080i/50 fps 1040 Uses the 1080i video format at 50 frames per second for the video trigger.
1080i/59.94 fps 1041 Uses the 1080i video format at 59.94 frames per second for the video trigger.
1080i/60 fps 1042 Uses the 1080i video format at 60 frames per second for the video trigger.
1080p/24 fps 1045 Uses the 1080p video format at 24 frames per second for the video trigger.
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trigger holdoff

The length of time the digitizer waits after detecting a trigger before enabling NI-SCOPE to detect another trigger.

Default: 0.00

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trigger delay

The length of time the digitizer waits after it receives the trigger to start acquiring data.

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line number

The line number to trigger on. The line number range covers an entire frame. The number of lines available depends on the format of the video.

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session out

Reference to the NI-SCOPE instrument session to pass to the next node in the program.

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error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Using Trigger Holdoff for Video Triggering

Use trigger holdoff to skip a specific number of frames between acquisitions. For example, to acquire a specific line number multiple times and repeat the same chroma phase, skip one frame in NTSC (121 ms < holdoff < 159 ms) and five frames in SECAM (201 ms < holdoff < 239 ms).

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application


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