Stop asynchronous read and write operations
You can write data asynchronously using the fprintf or fwrite function. You can read data asynchronously using the readasync function, or by configuring the ReadAsyncMode property to continuous. In-progress asynchronous operations are indicated by the TransferStatus property.
If obj is an array of serial port objects and one of the objects cannot be stopped, the remaining objects in the array are stopped and a warning is returned. After an object stops:
Its TransferStatus property is configured to idle.
Its ReadAsyncMode property is configured to manual.
The data in its output buffer is flushed.
Data in the input buffer is not flushed. You can return this data to the MATLAB® workspace using any of the synchronous read functions. If you execute the readasync function, or configure the ReadAsyncMode property to continuous, then the new data is appended to the existing data in the input buffer.