5-10 www.hp.com Technical Reference Guide
Input/Output Interfaces
5.6.2 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).
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.
Table 5-6.
USB Connector Pinout
Pin Signal Description Pin Signal Description
1 Vcc +5 VDC 3 USB+ Data (plus)
2USB- Data (minus) 4GNDGround
Table 5-7.
USB Cable Length Data
Conductor Size Resistance Maximum Length
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)
Table 5-8.
USB Color Code
Signal Insulation color
Data + Green
Data - White
Vcc Red
Ground Black