Technical data

48 DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes
3 Host Signal Quality Testing
The analyzed acquisition remains on screen and can be viewed by
moving or dismissing the results dialog box.
You can run tests when the oscilloscope is already stopped. This is
useful in the case of embedded hosts (and other cases) where the
device under test (DUT) may not easily be placed in a test mode, and
you want to analyze already acquired data.
See Also • Chapter 6, “Saving Test Results to an HTML File,” starting on page 81
Host Full Speed Connection
Perform these connection steps:
1 Attach the passive probes to the oscilloscope's Channel 3 and Channel 2
inputs.
2 Attach the SQiDD board to the root hub on the host under test.
3 Attach 5 self- powered hubs and a full-speed device to the same section
of the SQiDD board. If the section has a switch, it should be set to ON.
Hub #1 has to be a full-speed hub and hub #2 a Hi- speed hub. The
other hubs can be either full speed or hi- speed hubs.
4 Connect the oscilloscope Channel 2 probe to D+ probe point of the
device under test portion. Connect the oscilloscope Channel 3 probe to
the D- probe point of the device under test portion.
5 Exit the HS Electrical Test Tool if you have previously launched.
NOTE
Placing a full speed and/or a high-speed device downstream of a full speed hub forces both
to operate in full speed mode.