RAD Data comm ASM-20 - Manual (Page 55)

General Description B-1
Appendix B
IR-G.703 Codirectional
Interface (64 kbps)
B.1 Introduction
This appendix:
• Provides a general description of the IR-G.703 codirectional interface
(64 kbps)
• Describes the EXT mode
• Describes the INT/RCV mode
B.2 General Description
The IR-G.703 is an interface module for RAD modems, converting G.703
codirectional signals to TTL levels. The converted data is sent over the modem link
using the modem modulation technique and converted back at the other end into
G.703 64 kbps codirectional signals, or into any other digital interface signal
possible. The module is available in the following two versions:
• The Standalone version fits into a standalone modem and is available with
two types of physical connections: a terminal block or an RJ-45.
• The Rack version is mounted on the rack version modem card and uses the
modem edge connector for communication. The edge connector is wired, on
the motherboard of the card cage, to the DB-25 connector on the back plane
of the ASM-MN-214 card cage.
Figure B-1 illustrates the pinout of the
different connectors.
Byte sync is not kept end-to-end. A violation bit that is inserted every 8 bits does
not appear in the same location at the remote side.
Note