ucom/uplcom question

[Bernd Walter]

On Sat, Feb 12, 2005 at 04:30:07PM -0500, Marc Skarshinski wrote:
> I am having timeout problems on 4.9-Stable using the ucom devices
> provided by the "Prolific Technology PL2303 serial adapter (ATEN/IOGEAR
> UC232A), rev 1.10/2.02" and also the "Prolific Technology Inc.
> USB-Serial Controller, rev 1.10/3.00" driver.  I am trying to read/write
> to the port from a couple of shell scripts (one which cats the port, the
> other which issues printf statements to the port)
> 
> I think this has to do with improper port settings but I cannot get the
> settings, issued stty commands, to persist across printfs to the port.
> Are there locking devices which can/should be associated with these
> devices, analogous to the cuala locking devices for a cuaa device?

Under -current there are.
But for your case it's just enough to keep the device open.
e.g. with something like this:
(
	stty ...
	printf ...
	...
) > /dev/ucom0

> Also, the man page for ucom states: "The ucom driver shows a behavior
> like a tty", yet were this a standard serial port I would generally use
> a cuaa device not a tty.  Is a ucom suitable for controlling a device

cuaa* is the device name for sio driver.
Different names have ever existed for other drivers.
And yes - cuaa* devices are ttys as well as ucom* devices.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de