Motorola MTX8250LS 用户手册
Glossary-2
MRTI
Motorola Radio-Telephone Interconnect: a system that provides a repeater
connection to the Public Switched Telephone Network (PSTN). The MRTI
allows the radio to access the telephone network when the proper access code
is received.
connection to the Public Switched Telephone Network (PSTN). The MRTI
allows the radio to access the telephone network when the proper access code
is received.
MSK
Minimum-Shift Keying.
OMPAC
Over-Molded Pad-Array Carrier: a Motorola custom package, distinguished by
the presence of solder balls on the bottom pads.
the presence of solder balls on the bottom pads.
OSW
Outbound Signalling Word: data transmitted on the control channel from the
central controller to the subscriber unit.
central controller to the subscriber unit.
PassPort™
Enhanced trunking protocol developed by Trident Micro Systems that links
wide area dispatch networking.
wide area dispatch networking.
PC Board
Printed Circuit Board.
PL
Private-Line® tone squelch: a continuous sub-audible tone that is transmitted
along with the carrier.
along with the carrier.
PLL
Phase-Locked Loop: a circuit in which an oscillator is kept in phase with a
reference, usually after passing through a frequency divider.
reference, usually after passing through a frequency divider.
PPM
Parts Per Million.
PTT
Push-To-Talk: the switch located on the left side of the radio which, when
pressed, causes the radio to transmit.
pressed, causes the radio to transmit.
RAM
Random Access Memory: the radio’s RAM is loaded with a copy of the
EEPROM data.
EEPROM data.
Registers
Short-term data-storage circuits within the microcontroller.
Repeater
Remote transmit/receive facility that retransmits received signals to improve
communications coverage.
communications coverage.
RESET
Reset line: an input to the microcontroller that restarts execution.
RF PA
Radio Frequency Power Amplifier.
RIB
Radio Interface Box.
ROM
Read Only Memory.
RSSI
Received Signal-Strength Indicator: a dc voltage proportional to the received
RF signal strength.
RF signal strength.
RPT/TA
Repeater/Talk-Around.
Softpot
Software Potentiometer: a computer-adjustable electronic attenuator.
Software
Computer programs, procedures, rules, documentation, and data pertaining to
the operation of a system.
the operation of a system.
SPI (clock and data
lines)
lines)
Serial Peripheral Interface: how the microcontroller communicates to modules
and ICs through the CLOCK and DATA lines.
and ICs through the CLOCK and DATA lines.
Squelch
Muting of audio circuits when received signal levels fall below a pre-determined
value.
value.