ZETRON 640 DAPT XTRA, Installation And Repair Manual, Page: 164 / 210

Glossar
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Term Definition
Progress Tones
Different tones and beeps the paging terminal plays to callers to indi-
cate what the Model 640 is doing. Progress tones are invaluable when
troubleshooting paging malfunctions. Different tone sequences allow
the experienced technician to identify when an error occurred and
what the source of the error may be.
Prompts
A tone or voice message that guides a user through the paging
process, telling the user when and what type of action is appropriate.
Protocol
The rules of operation that govern a communication network.
PSTN
Public Switched Telephone Network. A commonly accessed domestic
telecommunications network provided by the telephone company.
PTT (Push-to-Talk)
On a mobile radio, the button that must be pushed to access the
communication system and transmit. On a transmitter, the signal input
that is used to key up the unit before sending data.
Punchdown Block
A terminal block that connects pairs of wire together by insulation
displacement. 66-type punchdown blocks are commonly used by
telephone companies to bring trunks (up to 25, 2-wire) into a building.
PURC® (Paging
Universal Remote
Control)
A protocol that defines the signals and key sequence used to control a
remotely located paging transmitter. The PURC

protocol is a trade-
mark of Motorola and is commonly used in paging transmitters.
Queue
The prioritized, orderly “waiting line” for access to a system. In
paging, the queue refers to the order in which pages are batched for
transmission - generally first in, first out (FIFO).
RF (Radio Frequency)
The portion of the electromagnetic spectrum used for audio communi-
cations (around 10 kHz).
RF Link
A communications interface between equipment by way of the radio
frequency. RF links are commonly used to send paging data to
remotely located transmitters to increase the coverage area.
Radio Station
The transmission equipment. The radio station includes all link trans-
mitters and receivers, paging transmitters, link controllers and any
other simulcast or encoding equipment used to get pages from one
place to another. In the paging terminal, the term refers generally to
the output section of the processor.
RAM Disk
Storage in the Model 640 for the voice prompts and database files. It
functions essentially like the hard disk in a computer. The RAM disk
is written to on boot up from the nonvolatile ROM disk.
Range
The usable coverage area of a radio system or transmitter.
READY LED
A light on the front panel of the paging terminal, indicating when the
Model 640 has completed its boot sequence and is ready for paging
input. It should be solid on at all times during normal operation.