🚀 go-pugleaf

Roland wrote:
> Hi,
> 
> I have a problem with the serial communication. I have to program a serial transfer which uses the RTS line to toggle the data direction of an RS485 device. So I need in principe a functionality like described for the DCB structure using RTS_CONTROL_TOGGLE for .fRtsControl. Now according to a ms-bug report (support.microsoft.com/support/kb/articles/Q140/0/30.asp) it doesn't work properly. As next step i tried using WaitCommEvent and its relatives (using EV_TXEMPTY) causing the result, that the process returns in the middle of the transmittion process and not at its end as described:"EV_TXEMPTY The last character in the output buffer was sent."
> 
> So I not able to control the RTS line in a suitable way.
> 
> Does anybody has a solution for this problem.
> 
> Roland  

Hi ROland,

Our software doesn't use RTS for much but we do need to control it to
signal external devices sometimes. We use the EscapeCommFunction()
in Win32. You call it with the handle of the comm port device and
either SETRTS or CLRRTS as the second argument depending on which
polarity you want on the line.

This means you have to do all this yourself without Windows handling
it for you, though.

Regards,

Jim Dodd
Onset Computer Corp.