Currently I am reading and writing data to the serial port using the async streams, no problems, everything is great. The issue I wanted to explore is currently I am reading the serial port via a Timer (polling every 300 ms.) I used to code in the .Net Compact Framework from Microsoft. The serial port method in the framework had a received byte threshold coupled with an addevent function. What this did was when I set the threshold to a certain number of bytes in the receive buffer, it would trigger an interrupt for a lack of better words, that then would automatically take the program to my receive function for processing, no timer or polling needed, this way the program could do other things without polling the receive buffer at a certain interval. Is there a way to implement this type of function in B4J, if not no big deal, it was a nice feature of the .Net Compact Framework.