"Tom Gardner" mars@tacks wrote in message
...
On 4/24/2012 5:27 PM, Karl Townsend wrote:
I'll chime in on this PLC thing. I have a lot of experience using
different different computer languages to control equipment.

I always found PLC ladder logic to be difficult and arcane. I do
know
the folks that do this can whip out a control program quickly.

If you don't have a fella with great aptitude for this sort of
thing
in house, I'd hire it out. An expert will charge ya, but it will be
worth it.

Karl

I'm at the age where I feel the need to challenge my brain to keep
it functioning. What control scheme would you learn if you were in
my shoes?

If given the choice I code a state machine controlled by global
Boolean variables, which roughly correspond to the relay coils. The
comments that describe its operation come first and replace a
flowchart.

I learned to decipher and then design relay ladder logic shortly
before PLCs came out.

jsw