Irrigation Example: Timer binding

Hi, I am working on an irrigation logic (fbd) and I have to add time set point for the process. Where should I bind that time set point so as my timer starts with the program?

Its a quick process, the linking happens in a simple ‘IF SCHEDULE THEN OPEN VALVE’ type program. First set up the outputs for each zone at Tab1, here we show 4 examples zones.

Next we build a schedule for each zone.

ANd finally a program to turn on the valve when the schedule is active.

Thanks for the reply…
And If I have to add a bypass (say one of my valves is malfunctioning and I have to replace it so I want my program to bypass that particular valve(zone) and move to the next and continue. What condition should I add? Will it be based on the valve status?

You will need a flow sensor to know that a valve failed, depending on the size of the pipe you might be able to make use of this water flow switch. If its smaller you’ll have to hunt around.

Once your controller knows about a failed valve condition it can start a timer and open the second valve when the time is right.

IF VALVE101 AND NOT FLOW101 THEN START V101FAIL
IF VALVE101 AND FLOW101 THEN STOP V101FAIL
IF TIME-ON( V101FAIL ) > 0:01:00 THEN START V101B

This is some very basic beginnings of the sequence but this will give you some ideas. The controller can handle pretty much any scenario and sequence you care to dream up.

1 Like

Thank you for the help.