User manual

Technical Reference
Campus-RS Fractional Interface Card User Manual A-11
X.21
Pin Mnemonic Description Direction
A* B†
8 SG Signal Ground Ground
1 FG Frame Ground Frame
2 9 SD Send Data To DCE
4 11 RD Receive Data From DCE
3 10 RS Request to Send To DCE
5 12 RR Receiver Ready From DCE
7 14 TT Terminal Timing To DCE
6 13 RT Receive Timing From DCE
* Pins provide a non-inverted signal.
† Pins provide an inverted signal.