Compaq W4000 Manual De Usuario

Technical Reference Guide 

 

5.7.3 USB CONNECTOR 

 
The USB interface provides two series-A connectors on the front panel and, on legacy-free 
models, three series-A USB connectors on the rear panel. 

 

 

4

 

3

 

2

 

1

 

 
 
 

 

 
Figure 5-9.   Universal Serial Bus Connector  

 

Table 5–19.   USB Connector Pinout 
 

Table 5-19. 

       USB Connector Pinout 

 

 

1 

Vcc 

+5 VDC  

3 

USB+ 

Data (plus) 

2 USB- Data 

(minus) 

4 

GND 

Ground 

  

5.7.4  USB CABLE DATA 

 

The recommended cable length between the host and the USB device should be no longer than 
sixteen feet for full-channel (12 MB/s) operation, depending on cable specification (see following 
table).  
Table 5–20.   USB Cable Length Data 
 

USB Cable Length Data

 

20 AWG 

0.036 

Ω 

16.4 ft (5.00 m) 

22 AWG 

0.057 

Ω 

9.94 ft (3.03 m) 

24 AWG 

0.091 

Ω 

6.82 ft (2.08 m) 

26 AWG 

0.145 

Ω 

4.30 ft (1.31 m) 

28 AWG 

0.232 

Ω 

2.66 ft (0.81 m) 

NOTE: 

For sub-channel (1.5 MB/s) operation and/or when using sub-standard cable  
shorter lengths may be allowable and/or necessary.

 

 
The shield, chassis ground, and power ground should be tied together at the host end but left 
unconnected at the device end to avoid ground loops. 
 
Color code: 

 

 

Signal Insulation 

color 

 

 

Data + 

Green 

  Data 

- 

White 

  Vcc 

Red 

  Ground 

Black 

 

 

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