Knowledge Base FAQ Item #3100140

Q3100140: I need to sense the DSR signal change. How can I do this?

ActiveXperts Serial Port Component is not event driven. You need to call the QueryDSR function to check the state of the DSR signal. If you need to check the state continuously, you need to call this function regularly, probably in a separate thread.

To monitor CTS (Clear-To-Send), use the QueryCTS function; to monitor DCD (Data-Carrier-Detect), use the QueryDCD function; to monitor RI (Ring-Indicator), use the QueryRI function.