Tektronix 784A Graphics Tablet User Manual


 
Brief Procedures
4–12
TDS 684A, TDS 744A, & TDS 784A Service Manual
2. Verify that the main trigger system operates: Confirm that the following
statements are true.
H The trigger level readout for the main trigger system changes with the
trigger-LEVEL knob.
H The trigger-LEVEL knob can trigger and untrigger the square-wave
signal as you rotate it. (Leave the signal untriggered, which is indicated
by the display not updating.)
H Pressing SET LEVEL TO 50% triggers the signal that you just left
untriggered. (Leave the signal triggered.)
3. Verify that the delayed trigger system operates:
a. Select the delayed time base:
H Press HORIZONTAL MENU.
H Press the main-menu button Time Base.
H Press the side-menu button Delayed Triggerable; then press the
side-menu button Delayed Only.
H Set the horizontal SCALE for the D (delayed) time base to 200 ms.
b. Select the delayed trigger level menu:
H Press SHIFT; then press DELAYED TRIG.
H Press the main-menu button Level; then press the side-menu button
Level.
c. Confirm that the following statements are true:
H The trigger-level readout for the delayed trigger system changes as
you turn the general purpose knob.
H As you rotate the general purpose knob, the square-wave probe-com-
pensation signal can become triggered and untriggered. (Leave the
signal untriggered, which is indicated by the display not updating.)
H Pressing the side-menu button Set to 50% triggers the probe-com-
pensation signal that you just left untriggered. (Leave the signal
triggered.)
d. Verify the delayed trigger counter:
H Press the main-menu button Delay by Time.
H Use the keypad to enter a delay time of 1 second. Press 1, then press
ENTER.