ZETRON 640 DAPT XTRA, Installation And Repair Manual, Page: 158 / 210

Glossar
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Term Definition
Glare
A condition caused when opposite ends of a loop start telephone line
are seized simultaneously. A glare condition results in misdirected or
incomplete calls.
Golay Sequential
Code (GSC)
A high-capacity digital paging format. Golay is registered to Motorola
and features advanced error-correction and fade resistance. The GSC
format supports tone, voice, numeric, and alphanumeric paging.
Ground Start
A telephone signaling protocol where a ground condition represents
seizure of the phone line by the originating equipment.
Group Call
A feature that allows several pagers in a specified group to be alerted
simultaneously. Group paging is commonly used for alerting emer-
gency response teams.
Guard Tones
PURC

tones that indicate the first part of the transmitter key up
sequence. Guard tones are sent by the radio station to effectively
“warm up” the transmitter.
Handshaking
The initial communications between modems to establish a connec-
tion. Handshaking allows modems to confirm communications para-
meters such as baud rate, parity, and number of stop bits.
Histogram
A statistical graph of paging terminal history produced by MCU.
Histograms for the Model 640 show the peak and average values for
each hour in the last 7 days.
Hook
Refers to the telephone cradle. A phone is idle in the on-hook condi-
tion and busy (in use) in the off-hook condition. Generally, loop
current flows during the off-hook condition.
Hot Installation
A method of adding circuit boards to the paging terminal while it is
currently up and running. Zetron paging terminals do NOT support
hot installation. The Model 640 must be powered down before any
cards are installed or removed to avoid damage to the products.
HSC (Hexadecimal
Sequential Code)
A paging format similar to 5/6-tone pagers. The HSC format supports
tone, voice, and numeric display pages and battery saver operation.
The HSC capcode combines a 5-digit address with a service block and
beep duration.
Hybrids
Two potentiometers that isolate the FROM TEL and TO TEL audio
signals. The hybrids (BAL R and BAL C) eliminate sidetone when
properly adjusted for the specific telco line impedance.
Immediate Start
A telephone signaling protocol that does not require a start indication.
The CO sends digits to the terminal immediately after the line is
answered.
Interface
A connection between multiple pieces of hardware equipment.