Tektronix TDS 600B Graphics Tablet User Manual


 
Triggering on Waveforms
3–98
TDS 500C, TDS 600B, & TDS 700C User Manual
Negative monitors the slew rate of the negative-going edges of pulses. The edge
must first cross the upper threshold and then cross the lower threshold.
Either monitors positive- and negative-going edges of pulses. The edge may
first cross either threshold and then cross the other.
Set the Slew Rate. The threshold levels and the delta time setting determine the
slew rate setting. To set these parameters:
1. Press TRIGGER MENU Type (main) Pulse (pop-up)
Class (main) Slew Rate (pop-up) Thresholds (main).
2. Press Set to TTL or Set to ECL (side) to set the upper and lower thresholds
to levels appropriate for those to logic families. ...OR...
3. Press the upper threshold button and, in turn, lower threshold button (side)
Use the general purpose knob or keypad to set the values for the high and
low thresholds.
Hint: To use the Trigger Bar feature to set the threshold levels on the pulse
edge, press DISPLAY Readout Options (main) Trigger Bar Style
(side) until Long appears in that menu item.
The threshold settings determine the voltage component of slew rate (Volts/Se-
cond). To finish specifying the slew rate, set the time component by doing the
following steps:
4. Press TRIGGER MENU Type (main) Pulse (pop-up)
Class (main) Slew Rate (pop-up) Trigger When (main) Delta
Time (side).
5. Use the general purpose knob or keypad to set the delta time value for slew
rate.
NOTE. The menu item Slew Rate in the side menu is not a button label; rather it
is a readout of the slew rate setting. This readout varies as you vary the Delta
Time setting this side menu and as you vary either of the threshold settings from
the Thresholds menu. You adjust those parameters to adjust slew rate; you can’t
adjust slew rate directly.