Fred McKenzie wrote in news:fmmck-CB580A.22112020062013@
5ad64b5e.bb.sky.com:

In article
,
Robert Macy wrote:

As I said, if light switches can be made
to be all down when off; it's easy to tell which light switch
activated the light. But, when you have a rack of switches in arbitray
positions and all your lights are out but one...

Robert-

I missed the earlier comments, but I see a point of confusion.

You're missing what Robert's *really* confused about... see below.

Do you want any one switch to be able to turn off the light if a
different switch turned it on? That requires a string of switches, with
the end switches in a SPDT configuration. Any intermediate switches
would be in a DPDT configuration. (There may be some 4 terminal
switches intended for this function.) As mentioned, you could swap two
wires at any one of the switches to give you "All Down Equals OFF".

But that would be of little value if you want to know which one switch
was responsible for leaving the light on.

Knowing which switch is responsible for leaving the light on is of no value to begin with. If the
light can be turned on OR OFF from any of multiple switches, WHO CARES which switch
turned it on? It. Does. Not. Matter.

For that, you would simply
connect all SPST switches in parallel. All switches in the up position
would need to be turned off for the light to go off. Then you would not
have "N-Way" switches where one of N switches could turn off a light
another switch turned on.

.... thus completely defeating the purpose of having multiple switches.