Triggering the Oscilloscope

To use TV triggering

If a more detailed analysis is required, then only one color field should be selected to be the trigger. You can do this by using the trigger Holdoff softkey in the trigger Mode/Coupling menu. Using the holdoff settings shown in the following table, the oscilloscope will now trigger on color field 1 OR color field 3 when Field 1 is selected. This is known as odd field selection. Even fields will be selected with Field 2.

Holdoff Settings

Video Standard

Fields/Picture

Holdoff Range

NTSC

4

33.5 ms to 50.0 ms

PAL

8

80.7 ms to 120 ms

SECAM

4

40.4 ms to 60 ms

PAL-M

8

80.4 ms to 120 ms

Triggering on Color Field 1 using Holdoff (single-shot)

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Agilent Technologies 54621A, 54621D, 24A, 42A, 22A, 41A manual Holdoff Settings