Motorola GM338 Service Manual page 52

G-2
OMPAC
OSW
PC Board
PL
PLL
PTT
RAM
Registers
Repeater
RESET
RF PA
RIB
ROM
RSSI
RPT/TA
Softpot
Software
SPI (clock and data
lines)
Squelch
Standby Mode
System Central
Controller
System Select
TOT
TPL
Over-Molded Pad-Array Carrier: a Motorola custom package, distinguished by
the presence of solder balls on the bottom pads.
Outbound Signalling Word: data transmitted on the control channel from the
central controller to the subscriber unit.
Printed Circuit Board.
Private-Line® tone squelch: a continuous sub-audible tone that is transmitted
along with the carrier.
Phase-Locked Loop: a circuit in which an oscillator is kept in phase with a
reference, usually after passing through a frequency divider.
Push-To-Talk: the switch located on the left side of the radio which, when
pressed, causes the radio to transmit.
Random Access Memory: the radio's RAM is loaded with a copy of the
EEPROM data.
Short-term data-storage circuits within the microcontroller.
Remote transmit/receive facility that retransmits received signals to improve
communications coverage.
Reset line: an input to the microcontroller that restarts execution.
Radio Frequency Power Amplifier.
Radio Interface Box.
Read Only Memory.
Received Signal-Strength Indicator: a dc voltage proportional to the received
RF signal strength.
Repeater/Talk-Around.
Software Potentiometer: a computer-adjustable electronic attenuator.
Computer programs, procedures, rules, documentation, and data pertaining to
the operation of a system.
Serial Peripheral Interface: how the microcontroller communicates to modules
and ICs through the CLOCK and DATA lines.
Muting of audio circuits when received signal levels fall below a pre-determined
value.
An operating mode whereby the radio is muted but still continues to receive
data.
Main control unit of the trunked dispatch system; handles ISW and OSW
messages to and from subscriber units (see ISW and OSW).
The act of selecting the desired operating system with the system-select switch
(also, the name given to this switch).
Time-Out Timer: a timer that limits the length of a transmission.
Tone Private-line.
Glossary