ViewSonic VP2650WB Service Manual page 40

3. USB Test Procedure
A. Introduction
The CATC UHT USB Hub Tester is a modular unit designed for use on the production
line to test USB Hubs for proper functionality according to the USB specifications.
The UHT tester performs the following tests:
1. hub enumeration
2. hub reset, suspend, and resume operation
3. connection and enumeration of a low-speed device(on each downstream port)
4. data loop-back integrity test with a low-speed device(on each downstream port)
5. connection and enumeration of a full-speed device(on each downstream port)
6. data look-back integrity test with a full-speed device(on each downstream port)
7. individual port suspend and resume operations(on each downstream port)
8. remote wakeup detection and propagation from each of the downstream ports
9. hub-initiated remote wakeup on connect/disconnect events
10. hub over current detection and reporting to the host
11. over current protection(gang or per-port configuration)
12. downstream current restoration(over current removed)
B. System Setup
Position the CATC UHT box on the test bench, near the USB hub to be evaluated. Connect the
DC plug of the AC to 5V DC@1000mA power converter to the +5V power receptacle of the
CATC UHT box. To activate the unit, plug the AC to DC converter into an appropriate AC
power outlet.
In the USB test system, connect the CATC UHT box as follow:
1. Connect a USB cable between the upstream port of the USB hub under test and the USB
port of the host PC.
2. Connect a USB cable between the first downstream port to be tested and the USB
connect to labeled "CH1".
3. Repeat step B for the next ports to be tested, connecting to "CH2", "CH3", "CH4" in
sequence.
C. Software Installation
Make a copy of the CATC diskette for backup, then copy its contents to the hard drive of the
USB-capable PC to be used as the test system host. The UHT software program (usb_uht.exe)
is a DOS application and must be run under the DOS operating system. It supports both UHCI
and OHCI USB host controller implementations.
To run the program, at the DOS prompt, type USB_UHT and press "Enter" key. The program
will clear the monitor screen and begin execution. During the test, the program displays the
test results on the monitor screen. To terminate the program and get back to the DOS prompt,
press any key.
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