Nikon RADIUS CM200 User Manual
Page 66
G-ii
Glossary
OSW
Outbound Signalling Word: data transmitted on the control channel from the
central controller to the subscriber unit.
PC Board
Printed Circuit Board
PL
Private-Line® tone squelch: a continuous sub-audible tone that is transmitted
along with the carrier.
PLL
Phase-Locked Loop: a circuit in which an oscillator is kept in phase with a refer-
ence, 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.
RAM
Random Access Memory: the radio’s RAM is loaded with a copy of the
EEPROM data.
Registers
Short-term data-storage circuits within the microcontroller.
Repeater
Remote transmit/receive facility that retransmits received signals to improve
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.
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
SPI (clock and data
lines)
Serial Peripheral Interface: how the microcontroller communicates to modules
and ICs through the CLOCK and DATA lines.
Squelch
Muting of audio circuits when received signal levels fall below a pre-determined
value
Standby Mode
An operating mode whereby the radio is muted but still continues to receive
data
System Central Con-
troller
Main control unit of the trunked dispatch system; handles ISW and OSW mes-
sages to and from subscriber units (see ISW and OSW).
System Select
The act of selecting the desired operating system with the system-select switch
(also, the name given to this switch).
TOT
Time-Out Timer: a timer that limits the length of a transmission.
TPL
Tone Private-Line
µC
Microcontroller