4
vacon • 20
Layout and connections
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
Figure 7. Ring topology
In the example below, the Ethernet communication will be interrupted to device number three and
other devices after that when the link is broken. The Fieldbus communication maybe faulted when
the link is broken, but when the switch enables the second designated port, the connections can be
reopened. In the RSTP protocol, it generally takes few seconds before the second designated port
will be activated. This depends on the BPDU exchange cycle, which is 2 seconds by default.
Figure 8. Ring topology: Error in network
NOTE!
The switch in Ethernet boards itself does not implement the RSTP protocol, so the network
will always need a third party switch to support it.
NOTE!
Do not use RSTP together with PROFIsafe. Recovery time in RSTP network can be several
seconds, and recovery time in STP network can be several tens of seconds. To compensate this, the
PROFIsafe watchdog time must be set long enough so that slow recovery time of RSTP network can
be tolerated. However, for example, in Siemens TIA portal, the longest PROFIsafe watchdog time
setting is 1920 ms, and this is too short for RSTP.
PLC
Managed switch with RSTP support
DRIVE
OPTE9-1
DRIVE
...
OPTE9-2
DRIVE
OPTE9-3
DRIVE
11661_uk
OPTE9-8
Power
1
2
DP
AP
3
4
5
6
7
8
PLC
Managed switch with RSTP support
DRIVE
OPTE9-1
DRIVE
...
OPTE9-2
DRIVE
OPTE9-3
DRIVE
11662_uk
OPTE9-8
Power
1
2
DP
DP
3
4
5
6
7
8
Summary of Contents for optea
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