Serial Port Connectors; Com1 Connector (Com1) - Xycom CHIP4e+ User Manual

CHIP4e+ Manual

Serial Port Connectors

There are two serial ports supported by the CHIP4e+ board.

COM1 Connector (COM1)

The nine-pin COM1 connector consists of two connectors (RS-232 and RS-485)
attached to one logical port. Only one connector can be used at a time.
The A after the pin number in the following table indicates the lower connector (RS-
232); B indicates the upper connector (RS-485).
For TXD termination, a 150Ω, ½-watt resistor must be connected from
pin 3B to pin 4B, with pin 1B connected to pin 3B and pin 2B connected
to pin 4B.
For RXD termination, a 150Ω, ½-watt resistor must be connected from
pin 8B to pin 9B with pin 6B connected to pin 9B and pin 7B connected
to pin 8B.
22
Pin Signal Pin
1A DCD1 1B
2A RXD1 2B
3A TXD1 3B
4A DTR1 4B
5A GND 5B
6A DSR1 6B
7A RTS1 7B
8A CTS1 8B
9A RI1 9B
Note
Signal
TXD-
TXD+
TXD TERM -
TXD TERM +
GND
RXD-
RXD+
RXD TERM +
RXD TERM -