Re: serial console and panic

[David Laight <david%l8s.co.uk@localhost>]

On Thu, May 07, 2009 at 12:56:55PM -0700, Paul Goyette wrote:
> Thomas E. Spanjaard <tgen%deepbone.net@localhost> wrote:
> 
> >If there is an earthing potential difference between the two machines
> >connected with a serial (RS232/null-modem) cable, the resulting
> >(mini-)surge will be interpreted as a break signal. You can prevent it
> >by using special cables or wiring a resistor between the ground
> >connections (iirc).
> 
> Back in the old days, we used optical isolators for just this reason.

And 20mA current loop ...

        David

-- 
David Laight: david%l8s.co.uk@localhost