BUG: RTS_CONTROL_TOGGLE Doesn't Cause RTS to Toggle

• Microsoft Win32 Software Development Kit for Windows 95

SYMPTOMS

Setting the fRtsControl member of the DCB structure to RTS_CONTROL_TOGGLE should cause the RTS line to go high when data is available for sending. When no more bytes are available for transfer, the RTS line should be set to low. In Windows 95, the RTS line stays high.

RESOLUTION

To work around this problem, use EscapeCommFunction to change the state of the RTS line manually. Because the system doesn't do the RTS manipulation, the application should implement the functionality itself. When data is about to be sent, the application should set RTS high. When all of the data has been sent, RTS should be set to low. This is only necessary when the device being communicated with requires it. For more information, see the Win32 documentation for help on EscapeCommFunction.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.