Topology - Danfoss VLT Series FC 102 Installation Manual

Installation

3.6 Topology

The PROFINET module features a built-in Ethernet switch
with 2 Ethernet RJ 45/M12 connectors. The module
enables the connection of several PROFINET options in a
line topology as an alternative to a traditional star
3 3
topology. The 2 ports are equal. Select and use the 2 ports
freely.
Star Topology
Illustration 3.5 Star Topology
Line Topology
In many installations, line topology enables simpler cabling
and the use of smaller Ethernet switches. The PROFINET
interface supports line topology with its 2 ports and built-
in Ethernet switch.
When line topology is used, take precautions to avoid
timeout in the PLC when more than 8 frequency
converters are installed in series. Each frequency converter
in the network adds a small delay to the communication
due to the built-in Ethernet switch. When the update time
is too short, the delay can lead to timeout in the PLC. Set
the update time as shown in Table 3.1. The numbers given
are typical values and can vary from installation to instal-
lation.
Numbers of frequency converters
connected in series
Table 3.1 Minimum Update Time
8
Minimum update time [ms]
<8
8-16
17-32
33-50
>50 not recommended
Danfoss A/S © Rev. 07/2014 All rights reserved.
Installation Guide
Illustration 3.6 Line Topology
NOTICE
In a line topology, activate the built-in switch by
powering all frequency converters, either by mains or a
24 V DC option card.
NOTICE
Installing frequency converters of different power sizes
in a line topology may result in unwanted power-off
behaviour while using controlword timeout (8-02 Control
Word Source to 8-06 Reset Control Word Timeout). It is
recommended to mount the frequency converters with
the longest discharge time first in the line topology. In
normal operation, the larger power size frequency
converters have a longer discharge time.
Ring/Redundant Line Topology
2
4
8
16
Illustration 3.7 Ring/Redundant Line Topology
MG90U402