[tech] Re: Door Works

[Simon Fryer]

Bingle

> A while ago David Manchester tapped:

[..]
> > Apparently the Eric was needed to place a load on the serial port. Cue
> > Mark ranting about poor quality PC serial ports.
> 
> Oh for the love of Glub, what the hell is going on?
> 
> Mark, this sounds extremely painful - what is the blackbox expecting
> & what's the PC making? I take it the Eric's providing somewhat of a 
> voltage drop?

Erics do a little more than voltage drop. I suspect that there could  be 
earthing probems. Erics provide a nice and convient way to pass current
to ground and the other data rail. Grab the DMM and go impedance checking
on the cables and connectors. 

See Ya
Simon

-- 
------------------------------------------------------------------------
"Well, an engineer is not concerned with the truth; that is left to 
philosophers and theologians: the prime concern of an engineer is 
the utility of the final product."  
Lectures on the Electrical Properties of Materials, L.Solymar, D.Walsh