Neptunek wrote

I want to build Wi-Fi network: one OC200 and three EAP225 (indoor) - and I want to EAP225 connect each other with mesh topology not wired patchcords. Can I do it?

Yes, you can do it. Latest firmware for EAP225 supports meshing.

However, note that using a mesh network limits the client capacity to the capacity of the mesh's root node. In other words: if you use mesh, the total client capacity of all meshed EAP225 is ~40 to 60 clients, while using cable to connect three EAP225 to the LAN you get three times this client capacity in total.