SMC PNEU ALPHA 2 (Mitsubishi)

Hi,

I've got this problem. 4 Zones irrigation.
There is a digital sensor A that starts the irrigation to Zone 1, and a digital sensor B that stops the irrigation.

Now i need to make a program that somehow counts the time that Zone has been irrigated, and replicates the same amount of time on each zone. Zone 2 should start immediately after Zone 1, and last for the same amount of time, and so on.

Also, in the meantime, whilst, say Zone 3 is getting irrigated, sensor A may call for irrigation again on zone 1, but until all 4 zones have been finished, it should not be allowed to start irrigating the Zone 1, and time remembering should start only when Zone 1 opens, not when the sensor calls.

Please anyone, help? I am a construction engineer, hydro, and civils, so can help there if anyone needs help.

Thank you,

JR

First you need to tells us what kind of controller you are using including the complete model number and any related hardware. Then you need to list all of the sensors that you will be using. How are you going to control the water flow, a pump? How will you start the pump and when? Then you need to write the sequence of events like:
1. Push start button starts the pump and
2. Zone one solenoid valve opens.
3. A timer runs for X amount of time.
4. Timer done zone one valve closes and zone two valve opens
and this process continues untill all zones are covered, etc.

SMC (Mitsubishi) ECC-PNAL2-24MR-D

Hi Craig,

Craig, you are right. I did not want to saturate you with the details, as i know a little little bit so i thought i MAY be able to fill the gaps, but that did not help you with the whole picture. So...

PLC "SMC" ( i think same as Mitsubishi model),
model ECC-PNAL2-24MR-D (PNEU ALPHA 2 )

It's got 8 digital inputs and 7 digital inputs, but they can all be digital.
It's got 9 outputs.

The setup:
-4 zones
-a pump that runs on the start of zone 1, and stops when zone 4 stops
-starting tray, which basically is a digital signal (water contact electrical loop): when water drops below the two pins and opens the loop it's sends a signal to start the irrigation. When water reaches the pins, it closes the loop and the signal it's sent to start the irrigation.

There is only ONE starting tray that dictate all four zones start and stop irrigation times. SO when the pins calls for irrigation, zone 1 valve opens and when the pins call to stop the irrigation, the zone 1 valve stops, and zone 2 valve is simultaneously opened, and it's stays open (the tricky for me bit) the exactly the same time that zone 1 valve was opened for...then it repeats for zone 3 and 4, each being irrigated consequently for the same amount of time that zone 1 was irrigated for.
There is also a little requirement, that if the sensor (pins) call for irrigation again, but the rest of the zones have not finished yet with irrigation of the previous cycle, to halt the opening of the zone 1 valve until zone 4 finishes, and then opens it, but the time starts to count when zone 1 valve opens (zone 4 finises) - not when the sensor calls for it.

Sequence:
1. Sensor calls for irrigation.

2. Z1 valve opens

3. Pump starts

4. ...count time somehow, and remember...

5. Sensor calls to stop the irrigation.

6. Z1 valve closes

7. Z2 valve opens, and stays opened for the same amount of time as Z1 valve from this cycle, and then closes

8. Z3 valve opens, and stays opened for the same amount of time as Z1 valve from this cycle, and then closes

9. Z4 valve opens, and stays opened for the same amount of time as Z1 valve from this cycle, and then closes.

10. Pump stops.

11. Timer (or something) that counts/remembers the Z1 open time needs resetting as it's getting ready for the next cycle.

All cycles will be randomly different (the plant will call for it).

The irrigation will have to start ONLY from 6am and stops at 6pm as a master control-clock timer.


I hope i did not scare you though...

Thanks,

JR

No fear here. First you need to have a good understanding of what your equipment can do for you. I am not familiar with that type of controller so you will need to find the programming manual and do the research. Once you get a feel for the controller you just have to put into code what you have just stated. The manual will tell you how to set up timers, inputs, outputs. If you don't know how to get started try the "Learn Plcs" section at the top of this web site to help you get the idea. It will probably be a different programming structure than the one that you will use but you will learn the basics. Then start trying to write some code based on your flow chart. Post your progress here and ask questions when you get stuck and we will see how we can help. Don't be afraid to get your vender involved, he may have a tutorial on programming the SMC controller.

The alternative is to hire an integrator to come in and do the work for you. It sounds like a relatively easy project and you will definately help yourself in the long run by knowing the nuts and bolts of your system. That is how a lot of people here have learned to work this majic box. Only you know your time constraints and can make the choice on how to proceed. You've got a good start so read the manual and get back to us.

Pneu Alpha2 Mitsubishi Irrigation

Craig,

I've red all the manuals, and i can basically do everything except how to have the zones 2,3 and four follow in sequence and each one being irrigated for the same amount of time as the zone 1. What FB should i use to "remember" the time that Zone 1 is open and than use that time?

My PLC has the following FB's:

Boolean, Set/Reset, Pulse, Alternate, Delay, One shot, Flicker, Time Switch, Counter, Compare, Offset Gain, Display, Zone Compare, Schmitt Trigger, Hour Meter, Speed Detect, Pulse Width Modulation, Retentive Alternative, Addition, Subtraction, Multiplication, Division, Calculation, Shift, SMS, Random One Shot, Delayed Alternate and Retentive Set/Reset.

It must be something really simple, but i can't figure it out, i am going out of my mind

Craig, anyone, can you help please?

Thanks,

JR

dedomane,

I don't have a background in function block programming, so take this with a grain of salt.

If the hour meter FB will work in the time base you need, use it with zone 1 as the input. Reset the hour meter with the on to off pulse FB using zone 4 as the reset input.

You will also need to use a boolean FB = sensor ! zone 2 ! zone 3 ! zone 4 to energise zone1. This is to prevent zone 1 from coming on when any of the other zones are on.

Use another on to off pulse FB with zone 1 as the input, use the output of this to a set FB for zone 2.

Use another hour meter to keep track of the time zone 2 is on.
Use a compare FB with the two hour meter times when they are the same use the output to a reset FB zone 2

Then just repeat the steps for zones 3 and 4

PS. If the hour meter won't work try using the flicker FB into a counter to roll your own hour meter.

It might just be me but this seemed a lot easier in ladder. I'm sure that the guys who do a lot of FB programming can do better.

.



.

Milldrone, my friend, you are an absolute GENIOUS! Thank you sooo much, i was loosing my mind! THANK YOU, THANK YOU, THANK YOU!

I was struggling a bit with your instructions, but i've read them few times, and they are so simple now, yet so SPOT ON!

I owe you.

Thank You,

JR:beerchug: