[Free][Windows only] UE4Duino 2 - Arduino (COM port) communication

Hi,
Is there a way to check how many bytes of data are available in the serial buffer to be read? Let’s say I have sent a float data (4 bytes) from the arduino to UE4, I would like to have my program on UE4 to keep checking the buffer until there are 4 bytes before reading it. Is there also a “read a specified number of bytes” function that would block until the specified amount of bytes has been read?
Thank you.