RAD Data comm RSD-20 operation manual Appendix a, Table A.1 X21 Interface Signal Description

		APPENDIX A
		Table A.1
	X21 Interface Signal Description
X.21		SIGNAL NAME	PIN
		SHIELD	1
G		GROUND	8
T		TRANSMIT	2
			9
R		RECEIVE	4
			11
C		CONTROL	3
			10
I		INDICATION	5
			12
S		SIGNAL TIMING	6
			13
-		EXTERNAL CLOCK	7
			14