[hpoj-devel] Re: ptal-printd init script for RedHat

[DG <dg...@um...>]

> From: pa...@rc... (David Paschal)
> Hi, Daniel.
>
> Daniel Gun wrote:
> > Does the device try to communicate with the computer when it is turned
on?
> > If so, the module could look for this signal and add the device when
turned
> > on.
> IEEE1284-compliant peripherals power up in compatibility mode with no such
> peripheral-initiated communication that you suggested.  In some cases you
> might notice a change in the status (peripheral-to-host) lines, but it's
> not guaranteed since different host and peripheral parallel ports have
> different pull-up or pull-down resistors.
>
> > Windows can handle having the device turned on or off arbitrarily.  How
is
> > it done?
> Windows tries to read the device ID string from the peripheral when it
> boots and when you invoke the "Add New Hardware" wizard, just as
> parport_probe does when it is insmoded.  I don't think Windows
automatically
> detects hot-plugging of devices on the parallel port the way it does with
> USB devices.

It may not detect hot-plugging, but my PSC500 is almost never turned on when
I start the computer.  I turn it on just before I am about to scan or print.
So, either Windows polls it at print and/or scan time, or else it has some
other way to know that the device was turned on.

In the former case, the answer would be to have hpoj poll the device each
time it is about to print or scan.

--
Daniel
ZZZ-dgun-ZZZ-@-ZZZ-umpire.com-ZZZ
(Remove the Z-'s to reply)
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