Technical data

www.westermo.com Theoretical and general applications 153
MAU Media Attachment Unit. Enables a device to tap into the LAN
Medium. Commonly the LAN medium used with this type of
interface is coaxial cable.This type of cable is referred to as to as
Thicknet or Thinnet.
MDI Medium Dependant Interface. An Ethernet port that allows con-
nection to other Data Communication Equipments (Switches,
Hubs etc) without the need of a null modem coaxial cable or
cross over cable.These can be referred to as uplink ports.
MDI/MDI-X auto An Ethernet port that detects whether the end port is a
MDI or MDI-X device and automatically configures the
port accordingly.
MDI-X Medium Dependant Interface – Crossover. An Ethernet port that
allows connection to other Data Terminal Equipment (PCs, PLCs
etc).
MIB Management Information Base. A database of objects that can be
polled or interrogated by a management system using SNMP.
MNP Microcom Networking Protocol, several methods for error cor-
rection and compression of data for telephone modems.
Modem Composite word of modulator and demodulator. A modem
modulates or converts the signal from computer equipment into
electrical signals for transmission. At the receiver there is a corre-
sponding modem that coverts the signals back again, demodu-
lates.
MSC Mobile Switching Center, switching station in a GSM network to
external networks for example, ISDN and PSTN
Multidrop One of the most common topologies for industrial data net-
works.
Multimode Technology for fibre-optic transfer where light waves are reflected
in the fibre core.
Multiplexer Also known as a wire saver, as it replaces 2 or more leased lines
with modems and one line by establishing independent channels.
NMT Nordic Mobile Telephony, earlier analogue mobile telephone net-
work.
NTP Network Time Protocol. An Internet standard that assures high
accuracy time synchronization to the millisecond of clocks located
in Ethernet devices.The protocol is based on TCP/IP.
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