Tektronix TDS5032, Manual

Page: 217 / 248

Measurement Algorithms
Figure 120: Equipment setup for Low Speed Downstream Signal Quality Host
Low Speed Signal Quality for HUB Downstream
To set up the equipment for Low Speed Signal Quality (hub) test, follow these
steps:
1. Connect the A plug dongle from the Inrush section of the test fixture to the
port of the unit under test (hub).
2. Connect the low speed test device to the A receptacle on the Inrush section
of the test fixture. Keep the Discharge switch always in the ON position.
3. Connect Ch1 of the D+ probe to the D+ pins on the Inrush section of the test
fixture.
4. Connect Ch2 of the D– probe to the D– pins on the Inrush section of the test
fixture.
5. Configure the measurement and select the command button to run the
application.
6. Select OK after acquiring a waveform. Verify that it is a correct waveform.
If the signal is clipped, follow these steps to increase the vertical scale:
1. In the oscilloscope menu, select Vertical>Vertical Setup to display the
Channel screen.
2. In the Scale field, increase the vertical scale values until the waveform is
completely displayed on screen.
TDSUSB2 Universal Serial Bus Measurement Package 203