Serious things

[Kevin Brown]

> OK I will repeat my question: Does Linux have a driver flag to toggle
> the RTS signal when there is data in the transmit buffer, similar to
> the Windows mode comX: rts=tg? This is very handy in RS-485 networks.
> All too often the Big system is busy and doesn't disable the
> transmitter soon enough to suit the embedded end. (i.e. its not real
> time.)

Kenneth's response to your last request:

"More information is needed.  You don't specify what does the
transmission and what kind of access you have to turn rts off.  You also 
don't specify what "rapidly" means.  Fast in the frame of human 
consciousness (e.g. 2 seconds), or fast in the realm of what the 
computer could do (e.g. milliseconds).

Since you mention gcc, I'll assume you have a C or C++ program that does 
the transmission.  If this is incorrect, ignore the remainder of the 
reply  :)

The only way you would have access to something like this from inside 
the program is through the driver.  You may already have opened the 
serial device and are using the driver to send the transmission.  The 
driver should have some provision (I would suspect an ioctl call, but I 
haven't used a serial driver this way, so wouldn't know without research).

There could be many different answers depending on what you have and 
where the control is done."