Table of Contents

1 INTRODUCTION

1.1	General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1

1.2Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1

1.3	Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.4Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

2 INSTALLATION

2.1	General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

2.2Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

2.3	Physical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

2.4Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

2.5System Synchronization and Clock Distribution . . . . . . . . . . . . . . . . . . . 2.5

3.4Operational Field Strapping Changes . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.5	Fault Isolation Procedure	3.3
4	THEORY OF OPERATION AND APPLICATIONS
4.1	Introduction	4.1

4.2Contention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1

4.3Sub-channel Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1

4.4	Control Signals		4.2
4.5	Applications		4.6
APPENDIX A X.21 INTERFACE SIGNAL DESCRIPTION
APPENDIX B X.35 INTERFACE SIGNAL DESCRITPION
FIGURES
Figure 2.1		Rear Panel	2.2
Figure 2.2		SD-20/V.35 PC Board Layout	2.4
Figure 2.3		RSD-20/X.21 PC Board Layout	2.4
Figure 2.4		Synchronization on Main Channel Modem’s Clock	2.5
Figure 2.5		Synchronization on Internal Clock	2.6
Figure 2.6		Synchronization on Sub-channel 1	2.7
Figure 3.1		Front Panel	3.1
Figure 4.1		Main Channel DTE with Sub-channel DCE	4.4
Figure 4.2		Main Channel DCE with Sub-channel DTE	4.4
Figure 4.3		Main Channel DTE with Sub-channel DTE	4.5
Figure 4.4		Main Channel DCE with Sub-channel DCE	4.5
Figure 4.5		RSD-20 Operating Modes	4.6
TABLES
Table 2.1		PC Board Switch and Strap Selection	2.3
Table 3.1		Control Functions	3.2
Table 3.2		Indicator Functions	3.2
Table A.1		X21 Interface Signal Description	A.1
Table B.1		V.35 Interface Signal Description	B.1

RAD Data comm RSD-20 operation manual Table of Contents