Is it possible to monitor the Data Carrier Detect line? There do not appear to be any facilities to access the status of this line.
According to the Microsoft doc https://msdn.microsoft.com/en-us/library/ff802693.aspx the CD line is the same as the RLSD line and you can monitor this via VAComm.MonitorEvents.ceRlsd = true and OnRlsd event.
Thank you. I'll give that a try.