Knx Pl-Link Room Bus; Bus Power Supply; Internal Knx Pl-Link Power Supply - Siemens Desigo TRA Engineering, Mounting And Installation Manual

Siemens
Building Technologies
12

KNX PL-Link room bus

The KNX PL-Link bus must be inside the building.
The cables must never leave the building.
The KNX PL-Link bus facilities communications from the PXC3 room automation
station to a maximum 64 devices on the KNX bus devices for various
manufacturers.
Note: The number of devices is also limited by the number of data points and the
available bus power.
Bus power is incremented during engineering with the ABT tool.
The KNX PL-Link bus basic version comprises one cable and two stranded bus
wires.
The PXC3 has one internal bus power supply of 160mA.
The DXR2 has one internal bus power supply of 50mA.
The PXC3 also includes an AC 24 V / 2A output for devices with increased
power consumption that is supplied via AC 24 V rather than via the KNX PL-Link
bus.
The KNX PL-Link is physically based on the KNX bus (Konnex).
In KNX networks area/line couplers and IP routers are not allowed.
Interconnection of room automation stations via KNX PL-Link is not admissible;
the connection is done exclusively via Ethernet switches (Section 9) or MS/TP
section 10).
The polarity of the KNX PL-Link bus conductors must be correct.
(KNX terminals + and –).
In most countries, specific /KNX know-how is transmitted through training centers
certified by the EIBA / KNX association (see

12.1 Bus power supply

A bus power supply is required for KNX bus communications. Throttled voltage DC
29 V is used.

12.1.1 Internal KNX PL-Link power supply

The room automation stations have an internal bus power supply, which is
switched on by default.
DXR2: 50 mA to supply approx. 5 KNX PL-Link devices
PXC3: 160 mA to supply approx. 16 KNX PL-Link devices
If an external supply is used, the internal supply must be switched off
manually via tool, as parallel operation is not permitted.
DXR2: If third-party KNX devices are integrated, we recommend switching off the
internal bus power supply via tool and using an external bus power supply.
Desigo TRA Engineering, mounting and installation
KNX PL-Link room bus
www.eiba.com or www.knx.org)
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CM111043en_09
2016-02-22