Possible to force Iterator subsystem to execute only once per time step?

I've created a Stateflow chart with an embedded Simulink PID controller. When I run the model, I get the error:

Function-call subsystem 'PID_Stateflow_Test/TestPID/StateOne.pid_control' cannot contain block 'PID_Stateflow_Test/TestPID/StateOne.pid_control/Discrete-Time Integrator' because this block requires a service that maintains the time that has elapsed between two consecutive executions. Since the function-call subsystem is being executed multiple times at t = 0, the concept of elapsed time is not well-defined between two such executions.

I assume this is because the embedded Simulink function is being called from the Stateflow state multiple times within a single time step. Is this true? If so, can I force the state du: function to execute only once per time step?

[Luigi Gervasio]

Have you fixed this problem? If yes, how?