Technical data

26 Notes on USB Electrical Compliance Testing
2 Preparing to Take Measurements
4 Attach the E2697A adapters or 1156A probes to Channels 2 and 3.
a When using the E2697A adapter, connect the 10073C miniature
passive probes to the E2697A adapter.
5 Turn on the oscilloscope to allow 30 minutes of warm up time prior to
use.
6 Configure the second monitor, if being used, while the oscilloscope is
warming up.
7 If the ambient temperature has changed more than 5 degrees from the
previous calibration, perform the calibration procedure built into the
oscilloscope (in the [Calibration… ] section of [Utilities] pull down
menu).
8 If the E2697A adapter is being used, compensate the passive probes
(see probe instructions).
9 Calibrate all the probes.
a If you will be performing hub hi- speed tests, calibrate out the skew
between the differential probes on channel 1 and channel 4 (refer to
oscilloscope instructions).
Single-Ended Connection
The following tests allow single- ended SMA connection measurements:
• Device Hi- Speed Signal Quality Test
• Device Hi- Speed Manual Tests
• Hub Hi- Speed Signal Quality Test
• Hub Hi- Speed Manual Tests
• Host Hi- Speed Signal Quality Test
• Host Hi- Speed Manual Tests
NOTE
These probe assignments will be used through out the entire test procedure.
NOTE
In certain test situations, there may not be a ground connection between the DSO and the
device under test. This may lead to the signal seen by the differential probe to be modulated
up and down due to the mid-frequency switching power supply. Connecting the DSO ground
to the DUT ground will be required to establish a common ground reference.