Filter subscribers

Applicable: TwinCAT from version 2.11, EL6601 from FW08, EL6614 from FW06

Depending on how the Ethernet network is configured, large or small numbers of the publisher telegrams being used there arrive at the EL66xx devices included in the network. At the start, the EL 66xx is configured by the EtherCAT Master to the subscriber variables that it is to receive: source AMS Net ID and ID of the variables are loaded into the CoE for each subscriber. The CoE objects 0x60n0:01 and 0x60n0:02 then respectively contain the AmsNetId and Variables ID to be checked. The EL66xx devices can therefore filter according to the incoming publisher IDs, and compare them with their own subscriber IDs. For this purpose the publisher variables contained in the Ethernet frames received are disassembled and checked individually.

If an incoming subscriber

• corresponds to a configured AMS Net ID and Variables ID, then the contents are transferred to EtherCAT via PDO.
• does NOT correspond to the above, then the contents are transferred as standard to the acyclic mailbox interface for transmission to the Master.

This is the standard setting of the EL66xx.

The second way generates a high acyclic EtherCAT transport load, because subscribers received by the EL66xx are transported that should not be transported by this EL66xx at all. For this reason the subscriber filter can be activated by the CoE entry 0xF800:02 = 0x0100 (bit 8 = TRUE). The subscriber data that do not correspond to the AmsNetID/Variables ID filter are then discarded in the terminal and are not transferred to the mailbox.

Filter subscribers Activation of the subscriber filter is recommended. Since the EL66xx needs to be re-initialized with each INIT-OP transition, it is essential to set the named CoE entry in the startup list.

Note: In this documentation, bit counting starts from 0: value.0, value.1, ...