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RAD Data comm ASM-10/8 User Manual

Page 21

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ASM-10/8 Installation and Operation Manual

Chapter 1. Introduction

09/10/00 16:26

Functional Description

1-7

Receiver

The receiver comprises several circuits, as shown in the block diagram,
Figure 1-6.

The receive filter removes all the out-of-band frequencies.

The automatic equalizer comprises several equalizers which are activated
according to baud rate.

The digital AGC automatically compensates for the attenuation of the
line.

Remote Power
Failure (RPF)
Indication

The Remote Power Failure feature notifies the user at a central location of
a power failure in a remote modem.
The remote power failure feature can be configured only when the
ASM-10/8 standalone unit (remote) operates in conjunction with the
rack-mounted card ASM-10/8/R (central). When a power failure occurs,
ASM-10/8 standalone unit transmits a special tone, which is detected by
the ASM-10/8/R and causes the RPF LED to turn on. A special push button
– RPF – located on the front panel of ASM-10/8/R, allows the user to reset
the RPF LED. The RPF jumper in the standalone unit enables or disables
the feature. RPF should be disabled for multipoint applications.

V.54 Diagnostics

ASM-10/8 features V.54 diagnostic capabilities for performing local analog
loopback and local and remote digital loopback. When the modem is set
to the digital loopback mode, the operator at either end of the line can test
both modems and the line. The loopback is controlled either with
front-panel push buttons or via pin 18 and pin 21 of the V.24/RS-232
interface.
A selectable option allows insertion of a delay into the data stream so that
the V.54 loops are not carried across the network.
A selectable option allows insertion of a delay into the data stream so that
the V.54 loops are not carried across the network. The delay prevents the
last modem from receiving the complete V.54 data sequence and, in turn,
being induced into the loop. V.54 delay is required only when operating in
synchronous mode.