You're going to have to elaborate a little more as to how your RFID device works.
Do you have to ask it to prepare to read the RFID chip?
If so, how do you do this?
Raise RTS?
Send a control byte/string?
If you read the RFID chip and the data is there, does it wait for RTS to be asserted and then raise its CTS and send data?
If so, you may have to use RTS/CTS handshaking.
Does it raise CTS and then just transmit its data anyway?
If so, use a Serial_OnCom event sub and ignore the fact that CTS is asserted.
Does it raise CTS, when data is ready, wait until RTS is raised by you
then transmit its data?
If so, use Agraham's SerialEx library (although did you alude to this with your Serial V1.2 title?) and use the SerialEx_OnPinChanged event, look for OnPinChangedReason=1 (CTS Changed) check it has been asserted and then raise RTS or whatever and capture the returned string.
serial.StopBits = [COLOR="Red"]17[/COLOR]
I hope this was a typo