Technical data

Testing Performance 2
4000 X-Series Oscilloscopes Service Guide 31
7 Press the User softkey to the right of the D7 - D0 softkey,
then turn the Entry knob ( ) on the front panel of the
oscilloscope to set the threshold test settings as shown in
Table 5.
8 Do the following steps for each of the threshold voltage
levels shown in Table 5.
a Set the threshold voltage shown in the User softkey
using the Entry knob on the oscilloscope.
b Enter the corresponding DC offset voltage on the
oscilloscope calibrator front panel. Then use the
multimeter to verify the voltage.
Digital channel activity indicators are displayed on the
status line at the top of the oscilloscope display. The
activity indicators for D7-D0 should show all of the
channels at digital high levels.
c Use the knob on the oscilloscope calibrator to decrease
the offset voltage, in increments of 10 mV, until the
activity indicators for digital channels D7- D0 are all at
digital low levels. Record the oscilloscope calibrator
voltage in the Performance Test Record (see page 61).
d Use the knob on the oscilloscope calibrator to increase
the offset voltage, in increments of 10 mV, until the
activity indicators for digital channels D7- D0 are all at
Table 5 Threshold Accuracy Voltage Test Settings
Threshold voltage
setting (in oscilloscope
User softkey)
DC offset voltage setting
(on oscilloscope
calibrator) Limits
+5.00 V +5.250 V ±1 mV dc Lower limit = +4.750 V
Upper limit = +5.250 V
–5.00 V –4.750 V ±1 mV dc Lower limit = –5.250 V
Upper limit = –4.750 V
0.00 V +100m V ±1 mV dc Upper limit = +100 mV
Lower limit = –100 mV