IBM XSERIES 220 ユーザーズマニュアル
Installing options
89
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.
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.
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 system board for attaching USB-
compatible devices.
compatible devices.
The following table shows the pin-number assignments for the USB-port connectors
on the system board.
on the system board.
Keyboard port
There is one keyboard port on the system board.
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).
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 system board.
on the system board.
Pin
Signal
1
+5 V dc
2
-Data
3
+Data
4
Ground
Table 11. USB-port 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
Clock
6
N/A
Reserved
Table 12. Keyboard connector pin-number assignments .
6
4
2
1
3
5