No events makes no sense - they work fine for me, with or without data. RThreshold > 0 is required to generate the event on incoming data, but control line state changes are there regardless. What is your _VPF.Autoyield setting? I have a feeling this VCOM layer ain't cutting it. FWIW, that HW Group freebie you pointed out has given me 2 BSOD's - the first in years.

Sorry, but I'm out of ideas.

>In my serial device for flow control I have Hardware (RTS/CTS).
>In my mscomm I tried everything for the handshaking.
>When I power the device off, onComm does not fire, it does not fire when I try to scan a barcode either.