User's Manual

12 - 8
RS232 Pin Configuration
Base/Host Port (DCE) IBM AT DB9
(DTE)
IBM XT DB25
(DTE)
Modem DB25
(DCE)
Pin / Input Signal
2 / (RD)
2 3 2
3 / (TD)
3 2 3
5 / (SG)
5 7 7
4 / (DTR)
4 20 6
6 / (DSR)
6 6 20
7 / (RTS)
7 4 5
8 / (CTS)
8 5 4
Refer to this table if you want to make your own cables.
To do so, you must determine if your host RS232 device is
• 9-pin or 25-pin and
• configured as a DCE or DTE device.
Serial Connector
The base connector is straight to the printed circuit board (PCB). The ninth pin sends 500mA at 5V power
out. This can power a peripheral device, such as a mobile printer, as long as that peripheral device can
accept 500mA at 5V.
Pin # Description
1 Internal Jumper to Pin 6
2 TXD
3 RXD
4 DSR
5 GND
6 DTR
7 CTS
8 RTS
9 5 VOLT OUT
Note: Signals referenced are for a DTE device.