Motorola VRS750, Service Manual

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ix
Glossary of
Terms
The following glossary of terms and definitions help you to understand the
VRS theory of operation.
Countdown
A term that describes the incremental step-down function of the counter in
the repeater. Approximately 500 milliseconds of time delay for conventional
modes and 1500 milliseconds for trunked modes separate each successive
delay state.
Delay State
The specific condition of the counter. A series of eight delay states prioritize
the repeaters within a common geographical area. Delay state zero has the
least time delay (0 milliseconds); delay state seven has the greatest delay
(approximately 3.5 seconds for conventional modes, and 10.5 seconds for
trunked modes). A unit that is in delay state zero is the priority unit.
Disable
The deactivation of the repeater. Press the VRS button on the control head or
switch the VIP input off.
Enable
The activation of the repeater. Press the VRS button on the control head or
switch the VIP input on.
Inhibit
A condition that occurs when the countdown sequence of the logic circuitry
of the repeater ends, or anytime the repeater stops transmitting.
Non-Priority
Repeater
A repeater in any delay state other than delay state zero. This unit is inactive
and does not repeat until the unit steps down to delay state zero.
PTT
The P ush- T o- T alk button on a portable radio or mobile microphone.
Priority Repeater
A repeater with its counter in delay state zero. This unit repeats any signal with
the proper carrier frequency and PL code.
Quick-Key
A short press of the portable’s PTT—one that is long enough for the VRS to key
the mobile and access the trunking system, but less than 1 second in duration.
Single Tone Burst
When a repeater enables, it transmits a 700-millisecond audible tone. This
tone burst increases the delay counter in all other repeaters within range of the
transmitting vehicle by one delay increment.