Re: SPDT remote controlled switch?

[RickH <passport@xxxxxxxxxxxxxxxxxxxxx>]

On Nov 21, 6:50 pm, "D&SW" <d...@xxxxxxxxxxx> wrote:
>  I use two PLC modules (X10 Appliance modules or "Universal" modules?) to
> control two double throw or single throw  relays. One relay switches power
> ON and OFF and the other relay selects the motor or motor winding (drape
> direction). Even if both relays energize,  only one motor (or motor winding)
> will be powered. The problem is, you will need some logic control to
> determine which direction the drapes should be energized in.
>
> "RickH" <passp...@xxxxxxxxxxxxxxxxxxxxx> wrote in message
>
> news:55b07181-30a8-4da2-a160-e88ef160abff@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
>
>
> > Is there a SPDT PLC switch available?  One that will absolutely
> > guarantee that both "throws" cannot become energized simultaneously.
> > I have drapes that have separate forward/reverse motors, currently
> > there is a simple hard-wired SPDT switch on the wall for open/off/
> > close, "Open" energizes the forward motor and "Close" energizes the
> > reverse motor.  Obviously energizing both motors simultaneously would
> > quickly destroy the motors and the drapery pulls.  So I need a PLC
> > switch with a true SPDT relay and 3 programmable "positions", IOW I
> > dont want to cobble togeter 2 SPST switches and risk having both
> > motors get energized simultaneously due to a communication glitch.
>
> > How can I convert this arrangement to PLC so I can have a remote
> > controlled drape?- Hide quoted text -
>
> - Show quoted text -

Thanks to both responders,

This is exactly the situation, I think I'll look for a pulse-toggled
latching relay for the motor selection side and a momentary or simple
on/off relay for the power.  The purpose of the center-off is to stop
the drapes at mid position.  The drapery track already has micro
switches that turn off the appropate motor at the outer and inner
limits based on cord position (as the pull cords age and stretch these
switches are easily repositioned).

The PLC market seems to have some big holes in basic switching
offerings, they go right from SPST to devices with all kinds of bells
and whistles, before they've created a basic set of foundation
products for switching.  A while back I needed a momentary contact PLC
switch and could not find that either.  I'd like to one day also get a
DPDT switch but dont suppose that will be easy either.

Basic switches (other than SPST) sound like a product opportunity for
someone wanting to license Insteon in their products (hint hint).