Alcatel-Lucent OMNIACCESS 740 - Manual (Page 28)

OmniAccess 740 Overview
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OmniAccess 740 Hardware User’s Guide
Alcatel-Lucent
S ERIAL L INE C ARD (V.35/X.21)
Serial Card (V.35/X.21) provides WAN termination for four ports over serial sync
interfaces. The card is a single slot line card, and is installed either in slot 0 or 1.
The card allows full duplex operation on a single copper pair and operates in
either DTE of DCE mode depending on the cable attached.
V.35 and X.21 are well known communication protocols over synchronous serial
lines.
V.35 Interface
The V.35 interface was originally specified by CCITT as an interface for 48kbps
line transmissions. It has been adopted for all line speeds above 20kbps.
V.35 is a mixture of balanced and common earth signal interfaces. The control
lines including DTR, DSR. DCD, RTS, and CTS are single wire common earth
interfaces. The data and clock signals are balanced signals.
X.21 Interface
The physical interface between the DTE and the DCE is defined in ITU-T
recommendation as X.21. The DCE provides a full-duplex, bit-serial, synchronous
transmission path between the DTE and the local PSE. It can operate at data
rates from 600bps.
1. V.35/X.21 Card LEDs
2. V.35/X.21 Port LEDs
3. 68 pin VHDCI Connector
4. Thumb Screw
Figure 9: Serial Line Card (V.35/X.21)
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