Hi,
For resolving sample time mismatch, you can use rate transition block to slow down or fasten up the sample time so as to bring in accordance to the output block.
In your model, you can put rate transition block just after the IF block which should match with the controller present inside subsystem, so that no changes inside the subsytem block has to be made.
For more info on usage of Rate transition, refer to following :
Hope it helps!
