Strobes

The professional outputs can be used as strobe outputs, generating signals synchronized with the video signals. This topic specifies the accuracy of the synchronization.

A strobe pulse is defined by 2 parameters: StrobePos sets the position of the strobe, and StrobeDur sets the duration of the pulse.

Strobe Position

StrobePos sets the beginning of the strobe pulse with regard to the vertical reference. Due to internal communication and processing time, there is a shift between the position of the strobe pulse as defined by the parameter and the effective occurrence of the signal. This shift is comprised between a minimum and a maximum as specified on the following figure and table.

StrobePosAccuracy

Strobe position accuracy

Strobe Timing Accuracy


Parameter	Video Standard	Measurement condition	Value			Unit
Parameter	Video Standard	Measurement condition	Min.	Typ.	Max.	Unit
Strobe position offset	NTSC / PAL	—	400	–	1400	μs

Strobe Duration

A strobe pulse is also defined by a duration through the StrobeDur parameter. The width of the pulse that is issued by the board will vary with regard to the defined value. This variation depends on the video standard and the I/O usage. These values are specified on the following figure and table.

StrobeDurAccuracy

Strobe duration accuracy

Strobe Timing Accuracy


Parameter	Video Standard	Measurement condition	Value			Unit
Parameter	Video Standard	Measurement condition	Min.	Typ.	Max.	Unit
Strobe duration accuracy	NTSC	one output only is used	-500	0	+500	μs
	NTSC	all outputs are used	-800	0	+800	μs
	PAL	one output only is used	-300	0	+300	μs
	PAL	all outputs are used	-600	0	+600	μs

Test Setup

The following figure shows the test setup used as reference for the strobe timing measurements.

StrobeAccuracySetup

Test accuracy setup