Introduction
TwinCAT EtherCAT Redundancy is an extension option for the TwinCAT EtherCAT master offering cable redundancy. From the last logical device, a cable is returned back to the master. The TwinCAT System Manager is used for configuration and diagnostics.
In case of a single cable break/detachment all slaves can still be reached either from the primary or from the secondary (redundancy) EtherCAT adapter. This fault has to be resolved before the next fault can be handled.
Now it is not possible to combine EtherCAT redundancy with Distributed clocks or with Hot Connect.
Configuration
The configuration of the redundancy can be done via the Advanced Settings of the EtherCAT-Adapter.
It is necessary to select a second EtherCAT adapter as the redundancy adapter. The adapter can be selected in the System Manager via the search button.
Also, the redundancy port needs to be declared, which is (the logically last EtherCAT slave), attached to the redundancy adapter. The System Manager shows all available EtherCAT ports of the EtherCAT slaves in a drop-down list.
See samples below.
Diagnostics
In case of a cable failure the break location can be detected via the SlaveCount (SlaveCount <> 0) and via SlaveCount2 (SlaveCount2 < CfgSlaveCount). CfgSlaveCount is located in the InfoData of the EtherCAT Master. These counters can be mapped to the PLC for evaluation.
Additionally, the states of the EtherCAT slaves can be evaluated. The break location is shown as a pair of missing links, on the outgoing port (i.e., Port B) of one EtherCAT slave and the ingoing port (i.e., Port A) of the logically following EtherCAT slave.
Sample A
The redundancy ring is closed via the Port B of the EK1110.
In case of a cable failure the break location is shown in the Topology View Online.
Sample B
The redundancy ring is closed via the Port C of the EK1101.
In case of a cable failure the break location is shown in the Topology View Online.
