9
Serial and Parallel Ports
PC/AT peripherals include two high-speed, RS-232C, 16550-compatible serial ports
and one bi-directional Centronics-compatible parallel port.
UART1 (COM1) accepts an RS-232 or a RS-485 connection (you can only use one
connection at a time). UART2 (COM2) can be used for one of the following three
options:
•
RS-232 out the 25-pin DB connector
•
Touch screen controller interface
•
Infrared (IR) interface
Use the BIOS setup menus to configure the port as a serial or infrared port. You can
use this port as both a serial and IR interface by allowing software to control the
connection.
Note
You cannot use UART2 as a serial and IR port at the same time.
If the touch screen controller is jumpered to use UART2 as a serial device, the 25-
pin DB connector cannot be used to interface to a device. These lines are combined
internally.
Note
The BIOS setup menus for UART2 must be set to standard operation to
use the touch screen controller on UART2.
Keyboard Ports
The keyboard port is routed to two separate connectors. One is a PS/2 connector,
allowing the keyboard to be routed out the side of the unit; the other connector
allows the keyboard to be routed to the front of the unit.
A polyswitch protects the +5 V on the keyboard port. This device opens if the +5 V
is shorted to GND. Once you remove the shorting condition, the polyswitch allows
current flow to resume.
Note
You can only use one keyboard port at a time.
