You are correct. As I recall the Teletype machine would sit there doing=20
idle cycles on an open line.
But I still like the 4-20ma standard!

On 12/3/2014 1:41 PM, Dwayne Reid wrote:
> Hi there.
>
> I'm pretty sure the above is not correct, at least for Canada.  I'm
> positive that a mark was 0 ma (open) and space was 20 mA
> (ish).  Might you be confusing this with industrial 4-20 mA current
> loops for analog data transmission?
>
> dwayne

--=20
John Ferrell W8CCW
    Julian NC 27283
  It is better to walk alone,
than with a crowd going the wrong direction.
                   --Diane Grant


--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.