Keysight InfiniiVision 2000 X Series, Service Manual

Page: 29 / 86

Testing Performance
2
2000/3000 X-Series Oscilloscopes Service Guide 29
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 53 ).
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 digital high levels. Record the oscilloscope calibrator voltage in the
Performance Test Record (see page 53 ).
Before proceeding to the next step, make sure that you have recorded the
oscilloscope calibrator voltage levels for each of the threshold settings shown
in Table 5 .
9 When testing 3000 X-Series MSOs, use the 8-by-2 test connector to connect
digital channels D15-D8 to the output of the oscilloscope calibrator. Then
connect the D15-D8 ground lead to the ground side of the 8-by-2 connector.
10 Repeat this procedure (steps 6 through 8) for digital channels D15-D8 to verify
threshold accuracy and record the threshold levels in the Performance Test
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