19 Jun
2009
19 Jun
'09
4:22 p.m.
On Friday (06/19/2009 at 07:08PM +0100), Tony Duell wrote:
You also need a ground don't you? Does this 4 wire cable have an overall
shield that you'll use for ground? or do you have to use one of the four
as the ground? In which case you really only get three signal wires...
I bring this up because I have actually fried line receivers (aka
1489-like devices) when two units were connected over a long cable
and powered from two different AC circuits and the ground over the data
cable was missing. Definitely a function of the design of the two things
being connected but a risk if you accidently omit the ground.
Chris
--
Chris Elmquist
Hi, I'd like to utilise an existing cable that runs between three floors in
the house which is similar to decconnect cable but only has
4 wires. My question is whether it is possible to run a serial cable between
a 90TL and a VT terminal using only four wires, and if so which four? If I
enable ^S/^Q flow control can I do without the outmost DTR/DSR pins?
I've not tried it, but I can't see why it wouldn't work. As you suggest,
you need the middle 4 pins o nthe connector. You _may_ need
to strap DTR to DSR (i.e. the outer pins on the MMJ) together at each
end, but I don;t think you do. DEC didn't normally use hardware flow control.