Viewing and Measuring Digital Signals 3
6000 Series Oscilloscope User’s Guide 121
function changes depending on which menu is displayed. For
example, when assigning Labels on digital channels the Entry
knob selects the channel to which the Label will be applied.
To change the logic threshold for digital channels
1Press the D15 Thru D0 key so that the Digital Channel Menu is
displayed.
2Press the Thresholds softkey
3Press the D15- D8 or D7 - D0 softkey, then select a logic family
preset or select User to define your own threshold.
The threshold you To change the logic threshold for digital
channels 121To change the logic threshold for digital channels 121set
applies to all channels within the selected D15 Thru D8 or
D7Thru D0 group. Each of the two channel groups can be set to a
different threshold if desired.
Values greater than the set threshold are high (H) and values
less than the set threshold are low (L).
If the Thresholds softkey is set to User, press the User softkey for
the channel group, then turn the Entry knob to set the logic
threshold. There is one User softkey for each group of channels.
For advanced information see “Digital channel signal fidelity:
Probe impedance and grounding” on page 340.
For information about replacement parts for the digital probe,
see page 345.
Logic family Threshold Voltage
TTL +1.4 V
CMOS +2.5 V
ECL –1.3 V
User Variable from –8 V to +8 V