HP 54620A, User'S And Service Manual

Page: 173 / 243

Step 3. To test the thresholds
1
Press
Logic levels
. Select
Chan 0-7
, under the
Set
softkey,
then select the
User
softkey under
Logic Thresholds
.
2
For each of the threshold levels shown in the following table, take
the following steps:
a
Use the Entry knob on the logic analyzer to select the threshold
voltage shown in the table.
b
On the function generator front panel, enter the DC offset voltage
shown in the table. Use the multimeter to verify the voltage.
The activity indicators for channels 0-7 should show all data channels
at a logic high.
c
Using the Modify down arrow on the function generator, decrease
offset voltage in 10-mV increments until all activity indicators for
channels 0-7 show the channels at a logic low. Record the function
generator voltage in the performance test record.
d
Using the Modify up arrow on the function generator, increase offset
voltage in 10-mV increments until all activity indicators for channels
0-7 show the channels at a logic high. Record the function generator
voltage in the performance test record.
3
Using the 8-by-2 test connector, connect channels 8-15 to the output
of the function generator.
4
Repeat steps 1 and 2, substituting channels 8-15 for channels 0-7.
5
Repeat steps 1 and 2 for the external trigger input, using the 8-by-2
test connector, and substituting the external trigger input for
channels 0-7 in the threshold menus.
Table 14 Threshold Test Settings
Threshold Voltage DC Offset Voltage
+5.0 +5.252 V
±
1 mV DC
–5.0 –4.748 V
±
1 mV DC
0.0 +0.102 V
±
1 mV DC
Testing, Adjusting, and Troubleshooting the Analyzer
Step 3. To test the thresholds
172