Hi Arthur,
It is to be noted that "BytesAvailable" and "NumBytesAvailable" behave the same way. They return the number of bytes available to read in the input buffer. When you say "I could access the input buffer and get all bytes using 'serial.BytesAvailable' which by default is 512", It is not true that the default value of the "BytesAvailable" is 512, the default value of the "BytesAvailable" property is 0. It is set to zero as soon you open the serial port by using the "fopen"' function.
It is difficult to understand what went wrong while you were using the "NumBytesAvailable" property of the "serialport" object without the actual code. Also, the "read" function is the equivalent of the "fread" function when you switch from "serial" to "serialport". Please refer to the following documentation about transitioning from "serial" to "serialport":
To know more about "serial" and "serialport", refer to the below documentation:
Hope this helps!
