Edge Triggering
TDS 620A, 640A, & 644A User Manual
Mode & Holdoff
You can change the holdoff time and select the trigger mode using this menu
item. See Triggering on page 2-13 for more details.
1. Press the TRIGGER MENU Mode & Holdoff (main) Auto or Nor-
mal (side).
In Auto mode the oscilloscope acquires a waveform after a specific
time has elapsed even if a trigger does not occur. The amount of time
the oscilloscope waits depends on the time base setting.
In Normal mode the oscilloscope acquires a waveform only if there is
a valid trigger.
2. To change the holdoff time, press Holdoff (side). Enter the value in %
using the general purpose knob or the keypad.
If you want to enter a large number using the general purpose knob, press the
SHIFT button before turning the knob. When the light above the SHIFT button
is on and the display says Coarse Knobs in the upper right corner, the
general purpose knob speeds up significantly.
You can set holdoff from 0% (minimum holdoff available) to 100% (maximum
available). See
Holdoff, Variable, Main Trigger
in the TDS 520A, 524A, 540A,
& 544A
Performance Verification Manual
, Section 2 on
Specifications, TypicalCharacteristics
for typical minimum and maximum values.
Holdoff is automatically reset to 0% when you change the main time base
time/division setting. However, it is not reset if you change the delayed time
base time/division (that is, when the time base setting in the Horizontal menu
is Intensified or Delayed Only).
See
Triggering
, on page 2-13.
See
Triggering
, on page 3-142.
For More
Information