Owner`s manual

MT56DSU2 Owner’s Manual
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D
Data Communications Equipment (DCE) — equipment that provides the function to establish, maintain
and terminate a connection. Additionally, provides the signal conversion required for communications
between DTE and data circuit or telephone line. See also “DTE”.
DDS (Dataphone Digital Service) — AT&Ts private-line end-to-end digital service, with data rates
(typically) at 2400, 4800, 9600, 19200, and 56000 bps. Now an AT&T “Accunet” family offering. The
DDS is a synchronous network that uses the ABATS test system, which requires little manual intervention.
default — the factory set position or value that a device assumes at startup. An alterable parameter.
digital loopback — a type of diagnostic test where the transmitted signal is returned to the sending device
after passing through a data communications link; the returned signal is then compared to the transmitted
signal.
DSR (data set ready) — an RS232 signal that indicates the DCE and line are ready to receive data.
DSU (Data Service Unit) — a device used to interface a user’s DSU to a digital circuit (such as DDS or
Ti). Used in combination with a “CSU’.
Data Terminal Equipment (DTE) —a device that provides output data in the form of digital signals. See
also “DCE”.
E
elastic store — an option that causes the DSU to allow for timing phase drifts in non-DDS applications.
F
four-wire circuit — two twisted-pair circuits with each pair transmitting signals in the opposite direction.
J
jumper — a wire that connects two or more pins; a configurable component on a printed circuit board.
L
leased line — a permanent communication line between a computer and a terminal providing private,
continuous access to the connection by a subscriber for a fixed fee.
LED (Light Emitting Diode) — a light source that emits visible light.
local loopback — a type of diagnostic test where the transmitted signal is returned to the sending device
after passing through a local communications loop; the returned signal is then compared to the transmitted
signal.