Specifications

Glossary
SCALANCE X-400 BA
152 Operating Instructions, 03/2009, C79000-G8976-C186-07
Mirroring
A port (mirror port) with its specific data traffic can be mirrored to another port (monitor port)
for test purposes. Protocol analysis devices can be connected to the monitor port, in other
words, the monitor port is not available for data exchange. Mirroring has no effect on the
mirror port.
Modes
Modes are discrete waves used to transmit data within a fiber-optic cable. With single mode
fibers, only one wave propagates, whereas in multimode fibers several waves propagate.
Modes are patterns of electromagnetic fields in FOCs.
MRP
→ Media Redundancy Protocol
Multimode
In multimode transmission, the pulse is transferred using many modes (waves) that travel
along curved paths or are reflected within the core. 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. Multimode fiber-optic
cables have an outer diameter of 125 µm and 50 or 62.5 µm core diameter. Due to the larger
core diameter the pulse edges degrade more than in single mode transmission resulting in
shorter transmission distances.
OSM
Optical Switching Module – SIMATIC NET Ethernet switch with optical ports.
Rapid Spanning Tree
The Rapid Spanning Tree protocol (RSTP) allows redundant transmission paths. This
prevents circulating frames and, if a fault develops, provides an alternative path within one
second (reconfiguration time).
Reconfiguration time
The time required to restore a functional configuration if a device fails or a network cable is
interrupted.
Redundancy client
Device in a ring topology that reacts to the test and reconfiguration frames of the
►redundancy manager.