Thursday, July 28, 2011

RS232 Pin-out and self make cable

The purpose of uploading the RS232 Pin-out is for anyone who wish to use laptop or notebook to connect DB9 pin D-Sub for hyper terminal to check/troubleshoot for NMEA serial signal availability or simulate NMEA out from latop to external device.
For new laptop which does not have DB9pin as serial com port, purchase of USB to Serial converter can be easily purchase from any computer shop. Solder a DB9pin female connector with 3 core cable will do the work. Pin 2 = Receive data, Pin 3 = Transmit data, Pin 5 = Ground. When using RS232 com port in laptop to measure RS422 signal on any external device, connect as below.

Laptop            RS422 device output
Pin 2 ---------------- TX-
Pin 3 ---------------- NC(Not Connect)
Pin 5 ---------------- TX+


Laptop            RS422 device input
Pin 2 ---------------- NC(Not Connect)
Pin 3 ---------------- TX-
Pin 5 ---------------- TX+