Basic function principles
The EP6601-0002 supports two types of Ethernet traffic, which can also be processed in parallel:
- Real-time traffic (Publisher/Subscriber, Beckhoff network variables, EAP)
- Sending network variables as Publisher. The box receives the network variables to be sent from the EtherCAT master via the cyclic EtherCAT traffic.
- Receiving network variables as Subscriber. The box forwards the received network variables to the EtherCAT master via the cyclic EtherCAT traffic.
- Non-real-time traffic
Non-real-time traffic is transmitted between the box and the EtherCAT master using acyclic EtherCAT mailbox traffic (EoE = "Ethernet over EtherCAT").
This transmission is throughput-optimized and, if necessary, with automatic fragmentation - by default, all telegrams that are not transmitted in PDO context are transported in the acyclic channel via EoE.
The EP6601-0002 cannot transport EtherNet Industrial Protocol (EtherNet/IP).
Data flow
The following diagram shows the data flow in the EP6601-0002.
1) A maximum of as many bytes are copied into the PDO as are configured in the PDO. If the data volume is higher, incomplete data may arrive at the controller. In the CoE object 0x60xx (for each Subscriber), the individual components can be added to the SubscriberFilter for "IgnoreItem":
- 0x60n0: filter values as value
- 0x60n2: corresponding filter value activated. Default: "VariableID" is activated
Cable redundancy
If the EP6601-0002 is operated in a system with cable redundancy, please keep the following in mind:
- real-time operation with network variables is possible.
- in the event of non-real-time operation with IP transfer, the IP traffic is routed via the primary EtherCAT port. Therefore the Windows IP settings of this port are also used.
If the link to this port is lost, IP communication to this port is currently no longer possible from Windows under TwinCAT 2 or 3.
It must therefore be avoided that the Ethernet connection between the primary EtherCAT port and the first EtherCAT slave fails, as otherwise IP communication via the EP6601-0002 is no longer possible.
