FAQ and common pitfalls

Can the master be used without an ENI file?

Unfortunately this is not possible at the moment. However, you can generate an ENI file using e.g. TwinCAT (by Beckhoff). See ENI files for details.

Why does the master lose frames and enter ERROR?

If the master cannot communicate with the EtherCAT devices properly, it enters ERROR for safety reasons, requests SAFEOP and keeps running (see State Machine). Raw sockets are used, and the communication only works if there are no other services present that use the interface simultaneously. Make sure that IPv4, IPv6, DHCP and other services are disabled on the network interface. You can check that by using wireshark.

Make sure that you configured the real-time parameters (priority, memlock, sleep state prevention…) properly (default values should be fine in most cases). See Configuration for details. A kernel with the PREEMPT_RT patchset applied is highly recommended. The Real-Time System Setup guide describes how to prepare a host for real-time operation.

However, some network interfaces and kernels are just not suitable for low latency raw sockets. This depends on the exact kernel version, network interface model, cycletime etc. You can contact us for support.

The application starts and keeps running but modifying PDOs using OPC UA is not possible.

Check that the master and all slaves are in operational (OP) state and check the logs. The master does not transition to OP automatically at startup. You have to explicitly request a transition to OP. If the network interface is not up or has no link, the master waits for the interface to become ready.

Running the Docker container fails with error XY.

Check that the docker container has all required capabilities (see Docker and Configuration for details).
You can also try to temporarily start the container as privileged.