Performing fread operation in Simulink

Hi every body

as you know if we use [A,count]=fread(obj) it gives us the nuber of read bytes in the count.

so we can find how many bytes we have read through the obj and so let us decide how to use them efficiently.

now there are ways to read through serial ports in the simulink like packet input, serial receive, stream input and ... but no one of them let us know about the length of data they have read and so we can not (at least in the case that i am working) use it properly

The question is about the way that we can determine the length of data we have read through a serial port in the simulink (exactly the role that count plays in [A,count]=fread(obj)]

any help on this subject will be appreciated. (I also appologize for the poor and weak english I wrote in-sorry for that)