OpenSprinkler Forums OpenSprinkler Unified Firmware OpenSprinkler Timer Operation

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    Hello All,
    Nwebie here, 1st post. I am very interested in purchasing an OpenSprinkler timer. I have had terrible problems with water hammer in my system, and I hope this timer can help. I need the timer to sequence my valves properly as detailed below to eliminate water hammer. Detailed below is how I would like the timer to operate:

    1.During startup, I would like the downstream zone valve to open first, and then open the master valve a few seconds later.

    2.Next, when switching from zone 1 to zone 2 for example, I would like the master valve to stay open and the valve for zone 2 to open a few seconds before the valve for zone 1 closes.

    3.When finishing the program on the last zone, I would like the master valve to close first, and the zone valve to close a few seconds after the master valve.

    I have been studying the OpenSprinkler timer on the website and understand that there are programmable timing delays for the valves. Would it be possible to have the timer sequence my valves as detailed in bullets 1, 2 & 3 above? If so, how would one set the software to operate the valves the way I want? Also, will my transformer from my current Rainbird timer work? It’s rated at 25.5VAC, 650mA. Sorry for the long first post.
    Thanks in advance,
    Joe M.



    1 and 3 can be done using the built-in features of the firmware (i.e. master on/off time). 2 is not a built-in feature, so you will have to modify the source code to achieve it.

    Another solution is to use the concurrent running mode (i.e. turn off sequential), where you can set the on/off time of each valve independently. However, one caveat is that while the ‘water time’ of a valve is on per-second granularity, the ‘open time’ of a valve is on per-minute granularity. For example, you can set valve 1 to open at 8:30, run for 55 seconds, and valve 2 to open at 8:31, run for 55 seconds and so on. Also you can designate any station as a master station, and set its open/close time.



    Thank you for the reply!
    I might be able to make the concurrent mode work for me. I would designate Zone 1 as the master. Does that mean I could just run all my valves as mini individual programs? Would OpenTimer be capable of operating my valves as I have detailed below? Obviously, a 1 minute delay between Zones is not ideal, but is preferable to water hammer!

    05:00:00 – Open Zone 2 valve
    05:00:05 – Open Master valve
    05:15:00 – Close Master valve
    05:15:05 – Close Zone 2 valve

    Then just do the same thing for the next valve one minute later:

    05:16:00 – Open Zone 3 valve
    05:16:05 – Open Master valve
    05:31:00 – Close Master valve
    05:31:05 – Close Zone 3 valve

    Thanks again!



    Wait, I thought you want the next zone to open a few seconds before the previous zone (your bullet 2). But in the example program you gave, zone 3 opens after zone 2 has closed. If this is the case, the firmware can already do this, and you can keep the controller in sequential mode. The firmware also supports fine tuning when the master valve will open. As I said in my previous reply: what’s not supported by default is opening a zone a few seconds before the next zone.



    Thanks Ray,

    Sorry for the confusion, I should have explained it better. In my last post, the sample program I posted was my solution to bullet #2 from my first post not being possible.




    Ok, I see. Going back to your earlier question: yes you can run your valves as many individual programs (assume Sequential mode is turned off). Alternatively, you can exploit the available features in Sequential mode to achieve or approximate what you want.



    😀 😀 😀

    Just wanted to update this thread.

    I got my Opensprinker controller. (like the new molded case a LOT) I replaced my RainBird ISM-9 timer with it. Luckily I had a phone jack less than a foot away, so I converted the line to Cat6 and plugged Opensprinkler into my gigabit home network. Powered it up with the transformer from the Rainbird and set it up for a fixed IP of

    The goal of this activity as stated before was to eliminate my problems with waterhammer. I had already installed waterhammer arrestors and they helped, but did not fully get rid of the problem. I became convinced that proper sequencing of the valves would take care of it….which is what lead me to Opensprinkler in the first place. I was experiencing waterhammer when switching zones and when the system shut down after the last zone ran.

    Sequential mode did not work for me, as I experienced terrible hammering when changing from one station to the other. What did work was concurrent mode. I have a master valve, and that was causing most of my issues with waterhammer. So what I did was to turn off the master valve function in Opensprinkler, and let it treat my master valve like any other station so I could get complete control of it.

    I set the master valve to run program 1 and to end a few seconds different than the last program, thereby giving me the delay I need. This eliminated the waterhammer I was having after the last program finished. To eliminate hammering when switching from one station to the other, I set the individual programs to overlap by 2 seconds. This causes the next valve to open before the previous one shuts. It took a lot of tweaking….but….WITH THE HELP OF OPENSPRINKLER, I HAVE COMPLETELY ELIMINATED WATERHAMMER!

    I could not be happier with Opensprinkler! The down side is that events need to happen in a very specific sequence for it to work, so you have to program it very carefully. Opensprinkler will do exactly what you tell it to do, so you have to make sure you know what you’re doing! Thank you Ray for a great product!



    Cool. Glad to hear that it helped solve the problem. Thanks for sharing your experience.

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OpenSprinkler Forums OpenSprinkler Unified Firmware OpenSprinkler Timer Operation