RTX51 can support 255 tasks to use in an application for diff. need. Hoevever, it will support only 19 (16 standard tasks and 3 fast tasks) to run at a time.
There are only 3 priority levels available. 0,1,2 for standard tasks and 3 for the fast tasks. If the tasks which are having the same priority are in active state, then time slice has to be used to schedule among these tasks...