Nonpreemptve scheduler

I want to use freertos to implement my priority based event driven state machine project. I will use each task as the event function for each event type and a messeage queue as the event queue for each task. Each task will wait for its events on its message queue. Can I assign different priority for each task in nonpreemptive scheduler mode (nonpreemptive priority based)?

Yes. Any task can have any priority between 0 and (configMAX_PRIORITIES - 1) no matter what other priority assignments there are in the same system. 0 is the lowest priority.