Tektronix TDS5000B Series - page 79

Performance Tests
TDS5000B Series Specificationsand Performance Verification 2-47
Setupper
andlower
limitsthat
ensure
triggering.
Thenchange
limitsuntil
triggering
stops.
Figure2 -19: Measurement of time accuracy for pulse and glitch triggering
3. Confirm that the trigger system is within the time-accuracy limits for
pulse-glitch or pulse-widthtriggering (time range >520 ns):
a. Set the upper and lower limits that ensuretriggering at 250 kHz:
HClick Upper Limit. Use the keyboardto set the upper limit to 4 s.
HClick Lower Limit. Use the keypadto set the lower limit to 500 ns.
b. Display the test signal:
HSet the Horizontal SCALE to 4s(5sfor TDS5054BE).
HSet the output of the sine wave generatorfor a 250 kHz,
five-division sine waveon the screen. Set the VerticalSCALE to
20 mV (the waveform will overdrivethe display).
HPressPUSH TO SET LEVEL 50%.
c. Check against limits: Do the following subpartsin the order listed.
HUse the multipurpose knob to increase the Lower Limitreadout until
triggering is lost.
HCHECK that the Lower Limit readout, after the oscilloscopestops
triggering, is within 1.9 sto2.1s, inclusive.
HEnter the time in the test record.
HUse the keypadto return the Lower Limit to 500 ns and re-estab lish
triggering.