Userland access to modem control lines?

Daniel O'Connor doconnor at gsoft.com.au
Wed Nov 17 06:49:21 GMT 2004


Hi,
Does anyone know of a way to manipulate the modem control lines from userland?
SVR4 has termiox and friends but I can't see an equivalent for FreeBSD.

The reason I ask is I am trying to talk to an RS485 bus - it is half duplex 
and the protocol converter uses RTS to control the data direction.

I have a kernel driver which handles this but it has it's limitations (eg 
takes over the port and boot up, only usable on certain devices).

I'm going to make it a line discipline eventually, but this was a stepping 
stone.

Thanks.

-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-hackers/attachments/20041117/9db435bb/attachment.bin


More information about the freebsd-hackers mailing list