Specifications

SCALANCE X-400 BA
Operating Instructions, 03/2009, C79000-G8976-C186-07
149
Glossary
Aging time
The aging time is the time after which a learned MAC address is discarded if a SCALANCE
X-400 has not received frames with this sender address during this time.
ARD
Automatic Redundancy Detection.
Autocrossover
Technique with which a TP port is automatically switched over between MDI and MDIX
assignment to make a connection independent of the port assignment of the device being
attached. This means that crossover cables are not required. The autocrossover function
can only be used when the port is set to autonegotiation mode.
Autonegotiation
Procedure standardized by IEEE 802.3 in which the transmission parameters (for example
10/100 Mbps, full/half duplex) are negotiated automatically between the devices.
CLI
Command Line Interpreter. Terminal-based configuration option for the SCALANCE X-400.
The CLI can be used both over the serial port of the CPU module and with TELNET over
every Ethernet port.
Collision domain
To ensure that the CSMA/CD protocol functions correctly, the propagation time of a data
packet from one node to another is restricted. This propagation time results in a spatially
limited span for the network depending on the data rate known as the collision domain.
Connection monitoring
With regular link test pulses, SCALANCE X-400 monitors the connected TP and FO cable
segments for short-circuits or interruptions. The SCALANCE 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 of storing the
configuration data. If the device is replaced, the configuration can be adopted by swapping
the C-PLUG.