Black Box 5000 - Manual (Page 260)

Multiserver 5000
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KTS, key telephone system — In industry usage, a
telephone system in which the telephones have
multiple pushbuttons to allow users to select
outgoing/incoming calls directly, without
dialing an access number such as 9. Generally, a
key telephone system has limited internal
telephone-to-telephone capacity. As related to
the Multiserver’s voice/fax module, a strapping
option for compatibility with KTS-type
telephone-interface equipment.
LCD, liquid crystal display — An 80-character
display in the front of the Multiserver unit that
consists of two 40-character lines. It displays
real-time status and alarm messages and the
time of day, and by use of the adjacent keypad,
it provides access to configuration, diagnostics,
and administration functions. The LCD is
standard on the Multiserver 5000.
leased line — A telephone line reserved for the
exclusive use of the leasing customer without
interexchange arrangements.
LF, line feed — A control character used to tell a
terminal device to go to the next line.
line-sharing device — A device with the ability to
differentiate between voice and fax signals.
When voice and fax share the same channel,
this device routes the output of the voice/fax
channel either to the telephone interface or to
the fax machine, as appropriate.
link — A communications circuit or transmission
path connecting multiple points in a network, a
composite. There are three types of link in the
Multiserver:
An Interconnect Link connects two
Multiservers, usually by an analog or digital
circuit provided by the telephone company.
A Mux Link connects a Multiserver to a
compatible multiplexor directly connected to
the Multiserver, or remotely attached using a
line driver, modem, or ISU.
An X.21 Link connects a Multiserver to a
compatible multiplexer via a pay-as-you-go link.
See X.21 bis.
local analog loopback — An analog loopback that
forms the loop at the line side (analog output)
of the local modem.
local channel loopback — A channel loopback that
forms the loop at the input (channel side) of
the local multiplexer.
local composite loopback — A composite loopback
that forms the loop at the output (composite
side) of the local unit.
local digital loopback — A digital loopback that
forms the loop at the input (digital side) of the
local modem.
loopback or loopback test — A type of diagnostic
test in which the transmitted signal is returned
to the sending device after passing through all,
or a portion of, the data communications link
or network. This allows the technician (or built-
in diagnostic circuit) to compare the returned
signal with the transmitted signal. This
comparison shows whether the equipment and
the transmission paths through which the signal
traveled are working.
mark — In data communications, a binary 1 state,
which is the steady, no-traffic state for
asynchronous transmission.
modem — Contraction of MOdulator-
DEModulator. A device that converts serial
digital data from a DTE to a signal suitable for
transmission over an analog telephone line, and
converts the received signal to serial digital data
for the DTE.
module — A printed circuit board and components
with specific functionality that plug into one of
the five module locations on the Multiserver.
module location — The chassis position of a
module in the Multiserver. The CCM is in
module location A, and there are four
remaining module locations (B, C, D, and E)
which can contain optional modules. The
optional NMS module fits underneath the CCM
and does not have a letter to indicate module
location.