Technical data

Device Signal Quality Testing 2
DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes 33
Device Low Speed Signal Quality Test
To set up and run the Device Low Speed signal quality tests:
1 Connect the USB Device, test fixtures, and equipment. See "Device Low
Speed Connection" on page 35.
2 Set up the test signal/packet that will be analyzed.
To set up the test packets used for compliance testing, see "Device Low
Speed Compliance Test Packets" on page 36.
3 On the oscilloscope's front panel, press the [Analyze] key.
4 In the Analyze Menu, press the Features softkey; then, select USB Signal
Quality.
5 Press the Te st softkey and select the Device Low Speed Signal Quality test.
6 Press the Signals softkey. In the USB Signal Quality Signals Menu:
a Press the D+ Source softkey and select the analog input source
channel connected to the D+ signal (channel 2 in the previous
connection instructions).
b Press the D- Source softkey and select the analog input source
channel connected to the D- signal (channel 3 in the previous
connection instructions).
Table 5 Equipment Used in Upstream Low Speed Signal Quality Test
Quantity Item Description/Model
1 Oscilloscope Agilent 4000 X-Series
3 Passive probes Probes included with the oscilloscope are
sufficient.
1 Host test bed computer Any computer with the Windows XP,
Windows 7, or Windows 8 operating system
and hi-speed USB ports.
1 SQiDD board Agilent E2646A/B
1low speed USB device Any USB mouse
5 USB self-powered hubs Any listed on USB-IF web site
6 5 meter USB cables Any listed on USB-IF web site