User`s manual
Chapter 2 Hardware Configuration 
Prox-1750 USER'S MANUAL 
Page: 2-7 
2-4. COM PORT CONNECTOR 
Four COM ports are enhanced in this board namely: JCOM1, COM2, 
COM3 and COM4.  JCOM1, COM3 and COM4 are fixed for RS-232 
while COM2 is selectable for RS-232/422/485. 
JCOM1 : COM1 Connector, DB9 male connector 
The JCOM1 Connector assignments are as follows : 
PIN ASSIGNMENT 
1 NDCD1 
2 RXD1 
3 TXD1 
4 NDTR1 
5 GND 
6 NDSR1 
7 NRTS1 
8 NCTS1 
9 NRI1 
COM2 : COM2 Connector 
The COM2 Connector assignments are as follows : 
ASSIGNMENT 
PIN 
RS-232 RS-422 RS-485
1 NDCD2 TX-  TX- 
2 RXD2 TX+ TX+ 
3 TXD2 RX+ RX+ 
4 NDTR2 RX-  RX- 
5 GND GND GND 
6 NDSR2 RTS-  NC 
7 NRTS2 RTS+  NC 
8 NCTS2 CTS+  NC 
9 NRI2 CTS- NC 
10 NC NC NC 
JCOM 1
5
10
1
6
COM2










