Function Call for a Reference Model in System Composer Archeticture

I am devoloping a model in system composer archeticture. Inside this model, there are to reference model software components and each reference model should be excute with different sampling time (for my example, fast loop is faster than slow loop with 10x). i was do that with a function call but it failed while running MIL or SIL.

Is there another method or reason for my problem?