Call an independent Simulink model from a Simulink model

Hello everybody, I have a Simulink model that I want to call another Simulink model on every simulation step. The parent model shall give initialization parameters to the second model which shall execute in its own separate simulation time. It shall then return a result value to the parent model which will use this generated value to continue the parent simulation.

Implementing this scenario as a submodel results in the submodel using the same simulation time point as the parent model. However I want the submodel to run for let's say 5sec during every simulation step of the parent model.

I hope this question makes sense and someone can give me a hint to how this is best implemented.

Thank you, Johannes