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Chapter 3. Installing Options
57
USB cables and hubs
You need a 4-pin cable to connect devices to USB 1 or USB 2. If you plan to attach
more than two USB devices, you must use a hub to connect the devices. The hub
provides multiple connectors for attaching additional external USB devices.
USB technology provides up to 12 megabits-per-second (Mbps) speed with a
maximum of 127 external devices and a maximum signal distance of five meters (16
ft.) per segment.
USB-port connectors
Each USB port has an external connector on the rear of the server for attaching USB
compatible devices.
The following table shows the pin-number assignments for the USB-port connectors
on the rear of your server.
Keyboard port
There is one keyboard port on the rear of your server.
Note: If you attach a standard (non-USB) keyboard to the keyboard connector, the
USB ports and devices will be disabled during the power-on self-test (POST).
The following table shows the pin-number assignments for the keyboard connector
on the rear of your server.
Table 5. USB-port connector pin-number assignments
Pin Signal
1 VCC
2 -Data
3 +Data
4 Ground
Table 6. Keyboard connector pin-number assignments
Pin I/O Signal
1 I/O Data
2 N/A Reserved
3 N/A Ground
4 N/A +5 V dc
5 I/O Keyboard clock
6 N/A Reserved
6
4
2
1
3
5