Agilent Technologies N5416A Manual de Serviço descarregar pdf (Página 217)

Low and Full Speed Tests 7

Notes on USB Electrical Compliance Testing 217

Connecting the Equipment The USB automated test application will prompt

you to perform these connection steps:

1 For 54831B/D and 54832B/D oscilloscopes, use 1165A passive probes.

For the 5485XA, 80000 and 90000A Series oscilloscpes, use E2697A

high- impedance converter with 10:1 passive probes, or 1156A active

probes.

2 Attach the passive probes to the oscilloscope's channel Channel 2,

Channel 3 and Channel 1 inputs.

3 Attach the SQiDD board to two USB ports at the end of 5 self- powered

hubs and a host system. Hub #1 has to be a hi- speed hub and hub #2

has to be a full speed hub. The rest of the hubs can be either hi- speed

or full speed hubs.

4 Attach a full speed device under test to the same section of the SQiDD

board. If the section has a switch, it should be set to ON.

5 Attach another full speed device to the adjacent section of the SQiDD

board. This is for triggering purposes.

6 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. Connect the

oscilloscope Channel 1 probe to the D+ probe point on the adjacent

device section of the SQiDD board.

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.

NOTE

Use a full-speed hub if device under test has embedded hub function. Otherwise the scope

will falsely trigger.

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Agilent Technologies N5416A Manual de Serviço Página 217