Can I implement SOEM on STM32F4 with connected Ethernet interface ?

Yes, it shouldn’t be a problem. The main focus for SOEM is small embedded targets with limited amount of memory. rt-labs has used several Cortex-M4:s together with SOEM.

Does SOEM contain everything I need to act as the Master and control the Slaves?

Most likely yes. First, it is good to know that SOEM is designed as a class B master (since it focus on small targets) which means that its missing some features that a Class A masters have. However, if you are about to develop an EtherCAT Master for an embedded device, all the features you are likely to need is there. We use it ourselves for quite advanced master projects.
The other thing to know is that SOEM is more of a library approach which means that you’ll have to write the application by yourself. This is usually what you want to do on an embedded target anyway, to be able to control when the frames are being sent and received for example.

You can look at the examples provided to see an example on how it’s being used. We can also help you develop with the application if you want to.

Is SOEM free for commercial use ?

Yes. However, SOEM is has GPLv2 license with an exception (see the source code for more exact wording) so it is something to be aware of. We can also provide you with a proprietary license if you prefer that instead. Please send a mail to

The processor, Ethernet card and application SOEM is that really all I need to control slaves in EtherCAT network ?