First real-world SCADA attack in US

Tue Nov 22 23:14:54 UTC 2011

----- Original Message -----
> From: "Matthew Kaufman" <matthew at matthew.at>

> Indeed. All solid-state controllers, microprocessor or not, are required
> to have a completely independent conflict monitor that watches the
> actual HV outputs to the lamps and, in the event of a fault, uses
> electromechanical relays to disconnect the controller and connect the
> reds to a separate flasher circuit.
> 
> The people building these things and writing the requirements do
> understand the consequences of failure.

If you mean "an independent conflict monitor which, *in the event there is
NO discernable fault*, *connects* the controller to the lamp outputs... so 
that in the event the monitor itself fails, gravity or springs will return
those outputs to the flasher circuit", than I'll accept that latter assertion.

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra at baylink.com
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