Trigger Delay - Philips PM3320 Operating Manual

4-99E
Trigger delay
TIME DIV positive trigger delay:
Range in 360 s/div .. 200 ns/div 4 1... 9999 div
Range in 100 ns/div ... 5 ns/div t 1... 500 div
With the trigger delay facility the time (in time or divisions) between triggering and the start of the
C.R.T. display (left-hand side) can be selected.
Example:
Suppose the 6th line in a TV pattern is desired (TV line = 64 us).
The required trigger delay is therefore 5 x64 us = 320 us (i.e. after the 5th line has been passed).
- Select TVF triggering.
- Set the TIME/DIV switch to position 10.us/div.
~ Select a trigger delay of 320 us or 32 divisions.
A delay of 320 us between the frame pulse and the left-hand side of the C.R.T. display is now
obtained.
This results in a display of the information of the 6th line.
TIME DIV negative trigger delay:
Range in 360 s/div .. 5 ns/div : -10 div
With negative trigger delay (pretrigger), selected, the trigger point can be chosen all over the ten'
horizontal divisions of the CRT screen. This enables to look at what happened before the trigger
moment.
NOTE: If the TIME/DIV switch is set to another position, the setting of the trigger delay
positive or negative and in time or divisions, will be automatically changed
(recalculated) and displayed in the top text area. The result of this recalculation is
rounded off downwards to whole divisions.
EVENTS trigger delay
Range : 1... 9999 events
In this mode which can be selected via the TRIGGER DELAY menu, the trigger can be delayed by
a number of events before a new signal acquisition is started.
These events have to be applied to the EVENTS/EXT CLOCK BNC input socket on the
frontpanel. The selected level on which these events pass is indicated in the TRIGGER
COUPLING EV/EXT CLOCK menu. it is also indicated by a mark E on the left side of the C.R.T.
Two predeterminded values can be selected by softkeys: TTL and ECL level.