Motorola PM1200, Basic Service Manual

Page: 131 / 138

6880309U09-A October 26, 2007
Glossary-5
programming cable A cable that allows the CPS to communicate directly with the radio
using RS232.
PROM See Programmable Read-Only Memory.
PTT See Push-to-Talk.
Push-to-Talk The switch or button usually located on the left side of the radio which,
when pressed, causes the radio to transmit. When the PTT is released,
the unit returns to receive operation.
radio frequency The portion of the electromagnetic spectrum between audio sound and
infrared light (approximately 10 kHz to 10 GHz).
radio frequency
power amplifier Amplifier having one or more active devices to amplify radio signals.
RAM See random access memory.
random access
memory A type of computer memory that can be accessed randomly; that is, any
byte of memory can be accessed without touching the preceding bytes.
read-only memory A type of computer memory on which data has been prerecorded. Once
data has been written onto a ROM chip, it cannot be removed and can
only be read.
real-time clock A module that keeps track of elapsed time even when a computer is
turned off.
receiver Electronic device that amplifies RF signals. A receiver separates the
audio signal from the RF carrier, amplifies it, and converts it back to the
original sound waves.
Receiver Back-End
IC A custom integrated circuit providing a digital receiver intermediate
frequency (IF) backend.
registers Short-term data-storage circuits within the microcontroller unit or
programmable logic IC.
repeater Remote transmit/receive facility that re-transmits received signals in
order to improve communications range and coverage (conventional
operation).
repeater/talkaround A conventional radio feature that permits communication through a
receive/transmit facility, which re-transmits received signals in order to
improve communication range and coverage.
RESET Reset line: an input to the microcontroller that restarts execution.
RF See radio frequency.
RF PA See radio frequency power amplifier.
ROM See read-only memory.
Term Definition