Siemens SIMATIC NET System Manual page 136

SCALANCE network components
4.5 SCALANCE X Industrial Ethernet Switches
Interface
LH+
ELH
Combo ports
Combo port is the name for two communication ports. A combo port has the two following
jacks:
● a fixed RJ-45 port
● an pluggable transceiver slot that can be equipped individually
Of these two ports, only one can ever be active. Using the mode, you can decide how the
ports are prioritized. The port name is the same on both jacks of the combo port, for example
"P3C". There is an LED for each combo port. The LEDs for the combo ports can be identified
by a vertical line and the word "COMBO". The labeling of the combo port LEDs does not
differ from that of the other LEDs, e.g. "P3".
IRT for strict real-time requirements
Devices with the IRT suffix (Isochronous Real Time) are particularly suitable for applications
in which a data transmission must be guaranteed at fixed intervals. For this to work, all
devices in an Industrial Ethernet have the same time base. The messages of the preferred
nodes are transmitted together at previously configured times. Frames of other nodes are
held back by the IRT switches and sent later.
Modular switches
For applications that require flexibility with regard to interfaces, the use of the modular
devices, such as SCALANCE XR324-12M, SCALANCE X308-2M and SCALANCE XR552-
12M, is recommended. By making use of media modules, modular switches provide
maximum possible variability.
Devices with bus adapters
The switch is equipped with bus adapter interfaces such as SCALANCE XF204-2BA.
Through flexible use of different bus adapters, the user can establish electrical and optical
line, star and ring structures.
Devices for special environmental conditions
Some switches are available in special designs so that they can be used in special
environments. This includes the design of the housing in IP65 with M12 plug-in connectors.
This version has the supplement PRO in the type designation. Switches with the supplement
EEC are approved for expanded environmental conditions.
136
Property
SC port 1000 Mbps single mode FO cable (up to max. 70 km).
SC port 1000 Mbps single mode FO cable (up to max. 120 km)
System Manual, 09/2019, C79000-G8976-C242-10
Industrial Ethernet