Service Manual

SRM9000 SERIES SERVICE MANUAL

APPENDIX A - GLOSSARY OF TERMS

A summary of common radio terms and some other terms used in this document, and their meanings, are

given below.

3RP Trunking Signalling Specification relating to trunked networks for shared use.

Used primarily for networks in France.

ADC Analogue to Digital Converter.

AFC Automatic Frequency Control.

AGC Automatic Gain Control.

Alarm A Selcall sequence sent from subscriber equipment to indicate an Emergency

situation.

When activated the radio will enter a repeating sequence consisting of an Alarm

Live Transmit Time and an Alarm Dead Receive Time.

Certain special conditions for the radio may also occur during the alarm.

A dedicated SFM (trunked system) that is sent by pressing the Alarm Key.

ANN Abbreviation for Algorithmic Network Numbering. This is the numbering system

where the numbers presented to the radio user can be mapped directly to the

MPT1327 PFIX/IDENTs and vice versa by use of a fixed algorithm in combination

with some other customisation parameters. See also FPP and MEP.

ANI Automatic Number Identification.

Auto Interrogate An Acknowledge identity sent as a response to an individual reset call.

Automatic Power Feature whereby the transmit power is automatically set to a level determined by

the level of the received signal. This is used to extend the battery life and/or

reduce radiated emissions.

Automatic Volume Feature whereby the background audio level is monitored and if this is found to be

noisy then the volume level is increased to compensate, allowing the user to hear

better.

Background Hunting The searching for an alternative and 'better' control channel whilst already on a

valid control channel.

BCAST MPT1327 broadcast message. Used to transmit information about the trunked

radio system to radio units.

Busy The state of a channel such that:

• For a non-signalling channel - if Busy this means that the carrier is above squelch.

• For a channel with CTCSS/DCS - if Busy this means a signal is being received

with either no CTCSS tone / DCS code or the correct CTCSS tone /DCS code.

• For a channel with Selcall - if Busy this means a closed channel where the signal

is above squelch.

A feature that equates to 'Do Not Disturb' such that the radio will reject all non-

emergency calls. This feature can be activated using the Busy key (if assigned) or

from a menu; it is reset to disabled at switch on.

C4FM Compatible 4-Level Frequency Modulation.