Roger,
Assuming contact ratings are ok, if, and
occasionally when I wish to control a
critical load, I plug one appliance module
into another, coded differently. Then to
turn on said load, I must sequence the codes
to get thru conduction to the load,
considerably lessening the chance of false
ONs, which are rare from my experience, and
closely matching Brian H.'s experience with
falsing, particularly with turning on when
not supposed to. Turning off must be
opposite sequenced, else one be left in the
on state, negating the redundancy.
I still would be very careful with large
loads being permanently connected and ready
to go unless personal monitoring is nearby,
all the time.... or if being falsely ON, it
won't do any harm but waste electricity.
Some of my experience is in the design of
failsafe systems in medical syringe pushers,
where a runaway is, to say the least,
intollerable. We used dual microprocessors
of different brands that both monitored
everything and talked to each other, plus
completely different software, authors, and
verifiers - in 1983!
