Siemens X-400 - Manual (Page 140)

Glossary
Operating Instructions for SCALANCE X-400 Industrial Ethernet Switches
140 C79000-G8976-C186-03
Connection monitor-
ing With regular link test pulses, SCALANCE X-400 monitors the con-
nected 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.
Digital input A digital input is used to acquire binary file information. A state change
can be logged in the Log Table or reported by E-mail or traps. The
voltage levels between – 30 V and + 3 V correspond to logical state "0“,
voltage levels between + 13 V and + 30 V correspond to logical state
"1“.
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 moni-
toring activated etc.). The modes can be switched over using a button
on the Switch CPU.
ESM Electrical Switching Module – SIMATIC NET Ethernet switch with elec-
trical ports.
Fault mask Specifies the desired status (good status). Deviations from this occur-
ring during operation are handled as faults.
FO port Fiber-Optic Port
Full duplex Two-way simultaneous - both communication partners can send and
receive at the same time.
Half duplex Two-way alternate transmission mode- it is only possible to either send
or receive over the interfaces at any one time.
Latency Latency specifies the time taken by frames to pass through a switch.
This does not include the time required for buffering frames.
Load Containment With its filtering functions, a switch makes sure that local data traffic
remains local. The local network load of a segment is contained in the
originating segment and does not represent extra load on the remain-
der of the network.