variable sized buffer simulink

hey,

I'm receiving variable sized data in each simulation step in simulink. However I need to wait a certain amount of simulation steps before I received the whole data package and therefore I need some kind of variable sized buffer. I have no information about the total amount of data, that I'm going to receive. The only information I got, is the amount of simulation step, that I have to wait until I received the whole data.

I've tried to implement it via a matlab function block and several delay blocks that delays the output data of the matlab function block for one simulation step. but always failing at the variable sized constraints (because the delay blocks doesn't support it) and I neither found any block that supports the functionality, that I need here.

Hope, you can help me out!