GARDENA Automatic 6 Zone Mechanical Water Distributor

[Rogers Watering]

I have a single station which is connected with a hose pipe to a GARDENA Automatic 6 Zone Mechanical Water Distributor. I have 4 (of a possible 6) hose pipes hooked up to this. The 4 hose pipes run 1 by one. Each time the water turns on, it switched to the next hose pipe. If I used fixed times, I can do a full watering with it on for 9 min and off for 1 min and then repeating three times.

If I introduce variable length watering (Zimmerman, etc), then I’d really like to say run for 9min * 100%, delay 1 min, and then repeat that three times. What is the best way to achieve this, or is it not possible?

Both methods of repeating seem to require fixed start times and if Zimmerman set the watering to 200%, then the programs would run into one another and I guess would result is longer runs on fewer zones maybe.

My fallback would be to spread the watering out to account for the 200% max clamping rule, that would work, but would just make the start-end full cycle longer for every run instead of just the >100% runs.

i.e. 100% = 9 + 1 + 9 + 1 + 9 + 1 9 vs 200% = 18 + 1 + 18 + 1 + 18 + 1 + 18

Notes:

Clamping Rule:
    * The final watering percentage is always limited between 0% and 200%.
    * https://openthings.freshdesk.com/support/solutions/articles/5000823370-use-weather-adjustments#zimmerman
Mechanical Water Distributor
    * https://www.amazon.com/Gardena-Automatic-Mechanical-Water-Distributor/dp/B006MWDQGA

[Ray]

In Edit Options -> Station Handling, there is an option called ‘Station Delay Time’. It inserts a fixed delay between every two zones. The delay time is fixed regardless of the watering percentage. I know you have just one zone, but there is a work-around to achieve what you want: you split the one zone wires into 4, and connect those to zones 1, 2, 3, 4 respectively. Physically it’s just 1 zone, but logically it’s 4. That way, you can set a program to turn on zones 1, 2, 3, 4 (which physically correspond to the same zone), but it will insert the delay time between them.

[Rogers Watering]

Thanks for the suggestion @Ray. Is it safe to basically short out the four station outputs or would I need to add a diode or something to each to make it safe? I’m being a bit cautious now as I was careless and already destroyed one of the stations 🙁

i.e.

Station 1     Station 2     Station 3     Station 4
    |             |             |             |
    |             |             |             |
  Diode         Diode         Diode         Diode       <-- See None 1 below.
    |             |             |             |
    |             |             |             |
    +-------------+------+------+-------------+
                         |
                         |
                       Valve
                         |
                         |
                      Common

Note 1: Would diodes or something ever be needed here to protect the station outputs from one another?

If this solution is electronically safe, it sounds like a super simple fix. I assume that serial runs would queue up in the order received and so I could set up the timing as follows for example?

• Station 1 @ Sunrise – 40 Min
• Station 2 @ Sunrise – 39 Min
• Station 3 @ Sunrise – 38 Min
• Station 4 @ Sunrise – 37 Min

This change in approach may also fix what seems like it could potentially be a bug I have with my current config where the first run has a differing water duration from the three subsequent repeats. I did notice that the Zimmerman Last Update time fell in between the first and second run, so maybe that is is the reason rather than a bug.

[Ray]

Are you using AC-powered OpenSprinkler, DC-powered, or Latch? For AC and DC powered, it’s safe to split a wire into 4 and insert them to zones 1, 2, 3, 4 respectively. Each port is logically a switch to ground, so if any port is active, that will activate the solenoid, there is no need to use diode — in fact, using diodes are NOT recommended (especially for AC as that will block half of the AC cycles).

If you are using OpenSprinkler Latch, I need to think a bit more about it.

[Rogers Watering]

I am using “Hardware Version: 3.2 – DC”, so it sounds like I am good to go.
Thanks!

[Rogers Watering]

Thanks again @Ray, this looks like it works as you described. It also look like I was overthinking the schedule. I can just run 1 program and have it start all four stations at the same time. The sequential logic queues them up one by one with the station delay in between each pair. This is probably better than I was hoping for 🙂

Attachments:

1. 

   Four-Stations-to-Same-Valve.jpg
   

[Ray]

Sounds good. Thanks for the update.

[Author]

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