Connecting remotely to end devices behind switch

Hello everybody,
before we will use VPN router Ewon cosy in our technology, we need to verify something.
Our technology has 12 end devices connected to one industrial switch (Siemens, not managed). We need to connect remotely to PLC, HMI and IPC (RDP application) which are in one subnet behind switch. The topology in this case is: VPN Router (Ewon Cosy) -> Switch -> end devices (PLC, HMI, IPC, servo drivers, etc.). Are we able to connect to IPC, HMI or PLC remotely if they are connected to the switch (via one LAN port from VPN router) and not directly to integrated switch (4 LAN ports) from VPN Router Ewon cosy?
Or do we need and managed switch and creates VLAN´s?

Thank you everybody for your help.

Tater

A post was merged into an existing topic: Remote access to IPC, PLC and HMI