Control valves logic

Somebody could give me some tips about realize a ladder logic to open and close valves.
Is a real simple logic but I have not enough experience in control logic.

Thanks so much.

xic input ote valve1

end

The more details that you provide us the more information we can provide you. You should incllude things like...
What brand PLC are you using.
How many valves...
What conditions are required before the valves open...
What conditions are required before the valves close....
ect.

What is the type of valve?
Is it on/off or proportional?

panic mode

They are solenoid valves (on/off)

Control valves

I need open/close the valves
The valves are controled in remote mode, in local mode they are inhabilitated.
They can be controlled in manual mode, in automatic mode they respond
to the system logic .
Exists an emergency stop command for each valve which inhabilite the
open/close actions.

Are you sure they're not "inebriated"?... P

Slowly but surely, you're giving us more of the info we need to help you... Please continue.

Questions:
Are these double-acting solenoid valves, or separate open/close valves?

You've got 4 different modes (5 if you include "panic mode")...
How do you select the different modes?

It would probably be easier if you could enlighten us by posting what you've got so far.

beerchug

-Eric

you need to build in a few features to your logic,
assuming valve feedbacks are normally open,
basic pseudocode as follows

if not output
and input
or
if output
and not input
=error 1

if error1
run timer 10 secs
if timer elapsed
set error bit

if acknowledge
reset error

if any interlocking valves open
=interlock bit

am assuming local/remote operation controlled by hand/off/auto switch

if auto position input
and auto activation required (from program)
or
if hand pos
and
not error bit
not interlock bit
=output

this is for one device
you need to get this into whatever plc you have, using editor and
test it for one device first.

get your client to supply list of interlocking valves, (usually stuff like a line drain valve and a product from tank valve can't be open together).
write up a document explaining planned device operation for approval

test first device and then copy/paste/replace for rest of devices.

tadg