RIO Remote I/O System User Guide
RTA connector pinouts
Page 205
Chapter 3 RIO Cabling information
DB25 male RTA connector pinout
Pin Signal Direction Description
2TXD Out Transmi t Data
3RXD In Receive Data
4RTS Out Request To Send
5CTS In Clear To Send
6DSR In Data Set Ready
7GND Ground
8DCD In Data Carrier Detect
20 DTR Out Data Terminal Ready
22 RI In Ring Indicator
Pin 1 (looking into connector)