Siemens SCALANCE X-300 Manual page 282

Glossary
Connection monitoring
With regular link test pulses, IE Switch X-300 monitors the connected TP and FO cable
segments for short-circuits or interruptions. The IE Switch X-300 does not send data to a
segment from which it is not receiving link test pulses.
C-PLUG
The C-PLUG (configuration plug) is an exchangeable memory medium for storing the
configuration data. If the device is replaced, the configuration can be adopted by swapping
the C-PLUG.
CRC
Cyclic Redundancy Check. A checksum used in transmission protocols to detect errors in
frames.
Cut Through
With this technique, a frame is forwarded as soon as the destination address is recognized.
The delay is therefore not dependent on the frame length.
Default gateway
A network node that forwards all frames not addressed to stations in the same LAN (subnet).
DHCP
DHCP (Dynamic Host Configuration Protocol), like BOOTP, a method for automatic
assignment of IP addresses. With DHCP, however, addresses can be assigned while the
device is operating.
Dispersion
Broadening and distortion of light pulses in fiber-optic cable due to signals arriving at
different times. On multimode FOC, the distortion of the output signal is greater than with
single mode FOC.
Display mode (DMode)
Display mode that indicates various statuses (port status, power monitoring activated etc.).
The display mode can be switched over using a button on the IE Switch X-300.
EEC
Enhanced Environmental Conditions
The device groups SCALANCE X-300EEC and XR-300M EEC are intended for use in
environmental conditions with enhanced requirements.
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Operating Instructions, 10/2010, A5E01113043-10
SCALANCE X-300