Ist there a recommended RTOS for netX90 and are there examples for RTOS available?
There are several ARM Cortex M4 compatible RTOS available in the market, however at this time Hilscher has limited experience with these and we do not have a RTOS example available for netX90.
Hilscher provides the CIFX-API and CIFX-Toolkit for developing the necessary drivers for your chosen RTOS. More information on the CIFX-API and CIFX-Toolkit can be located here: https://kb.hilscher.com/pages/viewpage.action?pageId=73208724
For FreeRTOS you may ask for help and further informations in their community forums: