Operating instructions

Glossary
Industrial Ethernet SCALANCE X-100 and SCALANCE X-200 Product Line
Glossary-4 Operating instructions, 09/2006, A5E00349864 Release 7
RMON
Remote Monitoring. RMON-compliant devices allow diagnostic data to be collected on the
device and read out by a network management station. This means that network problems
are detected early and can be eliminated. The particular advantage of RMON is that it is
independent of location. The acquired data can be analyzed at any point in the network with
suitable reporting software.
Segment
In the Ethernet bus system, transceivers connected together over the bus cable along with
the nodes connected over patch cables form a segment. Several such segments can be
connected via repeaters. When using twisted pair and fiber-optic cables, each subsection
forms a segment.
Signaling contact
Floating relay contact over which detected fault/error states are signaled.
Single mode
In single mode transmission, (and monomode transmission) the pulse is transmitted by a
straight mode (wave). Attenuation is mainly caused by physical absorption and dispersion as
well as by mechanical bending. The amount of attenuation depends, among other things, on
the wavelength of the input light. The single mode fiber typically has a core diameter of 5 to 9
µm. The outer diameter is, however, once again 125 µm (compare multimode). The smaller
core diameter degrades the pulse edges less than multimode transmission and allows
greater transmission distances.
SNMP
Simple Network Management Protocol. Standardized protocol for transporting network
management information.
Store and forward
An entire frame is received, its validity checked (checksum, length etc.) and then buffered.
Invalid frames are discarded, in other words, a frame is forwarded only when it is error-free.
TELNET
With this protocol, an interactive connection can be established to another device in the LAN
or on the Internet. The user then has the same options as when directly connected to this
device with a terminal.
TFTP
Trivial File Transfer Protocol. A simple, UDP-based protocol for data transfer. Due to its
limited size, it can also be used by network nodes with little ROM.