Virtual Serial Port Data Loss

Here is my problem I am using the serial command to read a virtual usb serial port. I need to read data at about 2 MHZ. However, it seems that matlab is unable to read the data without loss. I am wondering how to fix this problem.

Here are the following things I have tried

data.portObject = serial(portToOpen,'BaudRate',baudRate,'StopBits',1, 'InputBufferSize', 65536,'BytesAvailableFcn', @breakCallBack, 'BytesAvailableFcnMode', 'byte', 'BytesAvailableFcnCount',1024 );

Where break call back is

function breakCallBack(obj, event)
fread(obj, 8196, 'uint8');

I have obviously also tried to use a break interrupt function with no success even though my sending microcontroller was stalling in between data the function was never called.

I have tried switching the different numbers around to different values to see if the input buffer wasn't large enough ect.

I believe that the micro controller is sending 1 bit.

I tried different sorts of flow control and checked the number of data bits.

Does anyone have any insight as to why the communication channel is losing data when read by matlab?

I have checked the transferred data and it appears to be losing about 10% of the data being set.

I am willing to provide more information if neccesary.

[Walter Roberson]

I don't think I understand about "the micro controller is sending 1 bit" ?

[Walter Roberson]

Why are you firing your callback at 1024 bytes but asking it to read 8196 bytes ?

[Benjamin]

1) I meant that it is sending one stop bit. 2) I can change it it doesn't make a difference.

[Benjamin]

So i was using the larger number of bytes so that the function was not interrupted by a bytes available command in the middle of processing the input