Question for the PC guru's

[Bruce]

Is there a single pin/signal on a PC PCI bus I can toggle high or low to suspend PC operation without causing a re-boot?

We have a small relay card that waits to receive an IR code from someone wearing an IR badge. Once this code is received, the relays engage and connect the video, USB ports, PS2 for keyboard/mouse, etc.

This works great. If you don't have the IR badge, you can't use the PC. However, if I can control a pin on the PCI bus that suspends the CPU, I could really simplify the circuit.

Is this do-able?


Regards,

-Bruce

[tenaja]

I don't know about your specific hardware question, but why not use the badge as a password alternative, and have them log out when done. My laptop has a fingerprint reader... I'm sure you could replace the function with a badge reader.

[Darrel Taylor]

Because if they walk away without logging out, anyone can walk up and use it.

_

[tenaja]

Yes, that is an issue. You can set the screen saver at 1 min., but that is still enough time depending on the security needed.

There are programs that allow a one-key entry to the screen saver. Perhaps you could implement that when the badge is removed.

[Darrel Taylor]

I think this is for a busy environment, with busy/distracted people using the computer.

It has to "not work" when they walk away.

Bruce,

Stopping the cpu in midstream doesn't sound like a very good idea.
Especially with Windows.

Could be writing to disk or whatever at the time.

Just a thought ... You could simulate pressing the sleep button on a keyboard, to let the system enter stand-by when it doesn't see a badge. Then limit Mouse/Keyboard activity until it sees a badge again.

But that sounds difficult.

_

[Acetronics2]

Hi, Bruce

Why not simply "cut" the video signal at the input of the monitor ...

my monitor enters sleep mode when not receiving signals ...


did you ever try to work on a monitorless PC ...

Alain

[Luciano]

Hi Bruce,

Go to the Control Panel and select "Power options" "Advanced TAB".


(Click to enlarge the picture)

See also the hibernate TAB in "Power options".
Search in the Windows XP help file "hibernate".

Understanding Differences Between Hibernate and Stand By:
http://www.timeatlas.com/mos/Term_to..._and_Stand_By/

* * *

Note that in the BIOS there is also an option to change the function
of the power button. (On/Off or Suspend).

Regardless of the selected function of the power button, if the power
switch (button) is pressed for more than four seconds, the computer is
powered off. (Same as when you unplug the AC power cable).

Best regards,

Luciano

* * *

EDIT

The idea is to control the PC only with the power switch.
The PC will be powered on or waked up with the same power switch.
Your IR badge relay will be connected in parallel to power switch.
(The power switch is the push button on the front of the PC).

Before you can do that you will have to unselect the check boxes
that let you wake up the PC with the keyboard and the mouse.


(Click to enlarge the picture)


(Click to enlarge the picture)