ZETRON 640 DAPT XTRA, Руководство по установке и ремонту

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Glossary
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Term Definition
Decoder
A device that receives input data and translates it into a usable format.
Delay
The time difference between initiation of an event and the response.
Destination
The final paging terminal or coverage region (TNPP node address) for
which a page is intended.
Deviation Level
The range of variation of a specific tone level. The tone deviation is
usually set between 3.0 and 4.0 kHz for the Model 640 radio station
audio.
Dial Click
The audio data produced by a rotary dial telephone. The “clicks” are a
result of the phone line loop current being broken and reconnected.
Each digit is a series of one to ten clicks produced by a rotary phone.
Dial tone
A phone line condition that indicates to the calling party that the
exchange is ready to receive digits (either DTMF or MF).
DID (Direct Inward
Dial)
A type of phone line (from the CO) that transfers the last few digits of
the phone number dialed. A DID line allows direct dialing to a PBX
network without operator assistance.
DIG PTT LED
A light on the front of the paging terminal that indicates the digital
push-to-talk is active. The DIG PTT LED lights when the radio station
is sending digital paging data.
Disable
To make a feature or system inoperative.
Disable Tones
PURC tones that tell the transmitter to disregard the paging data to
follow. Also referred to as knockdown or death tones, they allow the
transmitter to only send pages intended for its area of coverage.
Display Message
The text that is sent to a numeric or alphanumeric pager.
DTR (Data Terminal
Ready)
An output signal that indicates to the receiving equipment that the
sender is ready to transmit data.
DTMF (Dual Tone
Multi-Frequency)
A common touch-tone protocol used in telephone equipment. DTMF
combines two voice-band tone signals into one “beat” frequency.
DTMF signaling provides 16 distinct signals.
Dual Trunk Card
A card that can be used in the paging terminal to provide two
incoming telephone trunk interfaces. Each half of the dual trunk has a
modem, a 9-pin serial port, and can be configured for DID, end-to-
end, E&M, or ground start signaling.
Dumb Terminal
A “brainless” computer. A dumb terminal consists of a monitor and a
keyboard. Often times a computer is made to look like a dumb term-
inal through the use of a terminal emulator software program. A dumb
terminal can be connected to the Model 640 to access the plus (+)
prompt commands and system databases.