Motorola SYMBOL MT2000 Series, Руководство по обслуживанию

Страница: 22 / 170

xvi
PLL Phase-Locked Loop; a circuit in which an oscillator is kept in phase with a
reference, usually after passing through a frequency divider.
PTT Push-To-Talk; the switch located on the left side of the radio which, when
pressed, causes the radio to transmit.
Registers Short-term data-storage circuits within the microcontrol unit or programmable
logic IC.
RESET Reset line; an input to the microcontroller that restarts execution.
RF PA Radio Frequency Power Amplifier.
RSS Radio Service Software.
RSSI Received signal strength indicator; a dc voltage proportional to the received rf
signal strength.
RX DATA Recovered digital data line.
SLIC Support-Logic IC; a custom gate array used to provide I/O and memory
expansion for the microcontroller.
SmartRib Use in conjunction with the RSS to read the Flashcode and Model Number, and
to flash upgrade radios.
Softpot Software potentiometer; a computer-adjustable electronic attenuator.
Software Computer programs, procedures, rules, documentation, and data pertaining to
the operation of a system.
Squelch Muting of audio circuits when received signal levels fall below a pre-determined
value.
SRAM Static-RAM chip used for volatile, program/data memory.
Standby Mode An operating mode whereby the radio is muted but still continues to monitor
data.
TOT Time-Out Timer; a timer that limits the length of a transmission.
TPL Tone Private-Line; Continuous Tone Coded Squelch System (CTCSS), industry
standard.
TSOP Thin Small-Outline Package.
µC Microcontrol unit (see MCU).
VCO Voltage-Controlled Oscillator; an oscillator whereby the frequency of oscillation
can be varied by changing a control voltage.
VSWR Voltage Standing Wave Ratio.