Re: [CAD_CAM_EDM_DRO] Twisted Pairs

Mariss and the list,

Good morning!

How about a differential pair? But then I guess that would be the same
signal!

Alan KM6VV


mariss92705@... wrote:

>
> Hi,
>
> I was talking to someone yesterday who was using a 10' twisted pair,
> sheilded cable for his encoder. He had used one pair for channels A
> and B, the other for +5VDC and ground. He called to say things
> weren't working very well.
>
> I suggested one pair be channel A and +5VDC, the other channel B and
> ground. He rewired it and called back to say everything was now
> running very well.
>
> The moral of the story is only one wire of a twisted pair should
> carry a signal; the other wire should be ground or supply. Otherwise
> cross-talk will get you.
>
> This is true also if twisted pairs are used for step and direction,
> limit switches or any other I/O use. It can be the cause of many
> mysterious malfunctions.
>
> Mariss