Anyone here controlling your grow room via PLC?

have you ever used one of those? they are cheap... are they reliable? how hard is it to calibrate them? I'm not sure thats what i'm looking for... the dwyer one goes from 0-2000ppm at 0-10v, which would be IDEAL for growing... this one goes to 10,000ppm, i would only be using the bottom 15% of its scale, so its calibration would have to be EXACT for it to be close to accurate. On another note, i finally got everything working perfectly with the PLC... whenever i'm ready to flower them, it will be a flip of a switch and all the timers will change... it was a pain in the ass redoing all the watering schedules for different times... now it wont be a chore at all...i'm lovin' it so far.

this is the only one i could find online... http://www.smarthome.com/3080/6-Inch-Diameter-Damper-Normally-Closed/p.aspx 6"-16" NO or NC powered by 24 VAC... its making me want to put a plc in the house to replace the thermostat

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I was writing this before i realized it was all here:

BloodShot420 said:

I am using a PLC, which runs my whole system... i spent a few hundred bucks on it, but it replaces all of the timers and controllers... and you write the program that runs on it yourself... the PLC controller is about $189.

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PLC controler, does that stand for "programmable logic controller". Is that like a little computer. I have used this little $40 thing that can be connected to a PC parallel port and has 8 relays on it. The problem is I would need the 12v relays to control power relays for the lights.
googling "PLC controler" brings up a lot of stuff. Could you give me some links to the stuff you used. Or maybe a DIY FAQ? That would be cool.

BloodShot420 said:

a solid state, self-calibrating co2 sensor from 0-2000ppm can be hooked up to it to read exactly how much co2 is in the air... this is also about $189

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I had the same problem googling "a solid state, self-calibrating co2 sensor"

BloodShot420 said:

then you need a co2 tank, with a pressure regulator (every soda fountain has one), and a solenoid... the solenoid is a valve that opens when the PLC tells it to, usually with some DC voltage... you should be able to get this setup for under $200... the regulator solenoid are about $50 each, but you can find them for less... and tanks are everywhere, and should be able to be found on the cheap. You would need this part no matter what co2 controller you went with.

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I have a regulator and a slonoid that works with 110v AC, I assume the PLC outputs a digital signal so I would need a digital relay or a new solonoid. I have the tank too.

there are lots of companies that make PLCs... allen bradley is probably the most popular, and possibly most expensive, honeywell is another big name... I am using one by "Eaton"...

here is their webpage showing their different logic controllers: http://www.eaton.com/EatonCom/Markets/Electrical/Products/LogicControl/ProgrammableLogicControllers/ELCControllersandModules/index.htm

i am using a "ELC-PA10AADR" (i'm pretty sure i got the last 4 letters right, the important part is elc-pa10) - you get add on modules for more inputs or outputs, outputs come in the form of either AC or DC... the AC is only 120v, the DC is 24v. On the controller you get 2 analog inputs, 2 analog outputs, 4 digital inputs (ac or DC, but all must be of same type), and 2 digital outputs (ac or DC, both same type)... if you need more you get addons..

the co2 sensor i was talking about is here: http://www.dwyer-inst.com/Products/Product.cfm?Group_ID=20017

that will hook up to one of the analog inputs on the controller, it transmits a signal of 0-10v, which is interpreted by the controller to correspond to 0-2000 ppm of co2.

if you solenoid requires 120v to open, you can use the 2 outputs on the controller as 120v output and use one to open that solenoid...

i bought a bunch of solid state relays that are triggered with DC voltage, so i added an 8 point digital output (which can work as either AC or DC as long as they are all the same)...

there is a catch - the ac outputs are good for only 1.5amps per point... which is why i went with all solid state relays and used dc voltage - so the plc cant get hurt by drawing too much current.

there is, however, an addon module that is has "isolated commons" which gives you only 6 points output, but each output can be either ac or dc voltage, and the 120v outputs can do 6 amps per point... the ending letters for that module are NNNI if memory serves.

Subscribed... i just started learning plc's... my next grow is in like a month .This will be my next project...

cool - what brand plc are you going to use?

BloodShot420 said:

cool - what brand plc are you going to use?

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Right now im using panasonic.... "Ara"something???
But i will soon get into allen bradley... it hasnt been that difficult but ive only worked with like 50 -60 steps...

ok... so i smoked some kush and i was asking myself.. Is there a way to monitor the ppm and have the plc audjust the nute solution ???????

thats a good question... i'm not sure about that yet, i think its a pretty neat idea... but i'm not quite sure i wanna hand that off to the PLC yet.

you would have to get something that hooks up to the plc, that can release a certain amount of nutrient into the res... i have no idea what that would even be called, but if you used a bunch of different nutrients, you would have to buy one of those things for each nutrient...

also, i use some powder nutrients, that prob wouldn't work with those...

but i do think it would be pretty kick ass to be able to load up your hydro system with nutrients, and automate it to handle everything, from draining/refilling res, to lifting the lights, then you could just put them in there, forget about them and come back in 2 months and they would be ready

allen bradley is prob the most commonly used i hear - it would be a good one to learn.

I'm using the Eaton brand - they are pretty small and pretty cheap comparatively... not sure how much you can get an allen bradley controller for now. The eaton one is about 215 with a power supply, and add-ons are pretty cheap, except for the thermocouple addon, which is 189... the analog inputs are on the controller though, so co2, or res ppm would be possible with no addons...

BloodShot420 said:

thats a good question... i'm not sure about that yet, i think its a pretty neat idea... but i'm not quite sure i wanna hand that off to the PLC yet.

you would have to get something that hooks up to the plc, that can release a certain amount of nutrient into the res... i have no idea what that would even be called, but if you used a bunch of different nutrients, you would have to buy one of those things for each nutrient...

also, i use some powder nutrients, that prob wouldn't work with those...

but i do think it would be pretty kick ass to be able to load up your hydro system with nutrients, and automate it to handle everything, from draining/refilling res, to lifting the lights, then you could just put them in there, forget about them and come back in 2 months and they would be ready

allen bradley is prob the most commonly used i hear - it would be a good one to learn.

I'm using the Eaton brand - they are pretty small and pretty cheap comparatively... not sure how much you can get an allen bradley controller for now. The eaton one is about 215 with a power supply, and add-ons are pretty cheap, except for the thermocouple addon, which is 189... the analog inputs are on the controller though, so co2, or res ppm would be possible with no addons...

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Medical dosing pumps would be ideal. Basically all they are is some IV tubing run in about 270 degree rotation (inside a block) and a rotor that just squeezes the tube pumping th fluid through the tubing (probably bad explanation) But they are pricey. (used to make them when I was a machinist) Other concern is you really don't want your probes sitting in the solution all the time.

Maybe 2 shot glasses with the solution pumped in and then tap water pumped into them after the readings. (don't use ro or distilled to store a pH probe in)

Thermocouples are about the most accurate, but over kill with the added expense of the module. You can use a simple thermistor (and slight conditioning) into a A/D and kill other birds with the extra A/D channels.

AB is king of the hill in the US, but Siemans and Modicon are it in Europe.
(Modicon hit me up to be Senior product manager)

Solenoids...Why didnt i think of this before?...I had a project about three years ago where paint had to be mixed to make different colors.....and i used some solenoids with float switches and a timer ... i got an "A" on that...

i like that idea about moving the lights also....

Check this out .... They have ph meters , PPM , Humidity even airflow sensors...
http://www.eidusa.com/Interface_Boards.htm

This sounds good ... you snuck in your reply before me...LOL...

BigBudBalls said:

Medical dosing pumps would be ideal. Basically all they are is some IV tubing run in about 270 degree rotation (inside a block) and a rotor that just squeezes the tube pumping th fluid through the tubing (probably bad explanation) But they are pricey. (used to make them when I was a machinist) Other concern is you really don't want your probes sitting in the solution all the time.

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Periostaltic pumps might be a bit overkill when you could probably get away with a normal small pump using supplimental solution resevoirs at maybe 10x desired final concentration..
As for the probes, if they are going to be permanently submersed, they will need to be gold/platinum.. Actually any probes for tds should be precious metal..
http://www.octiva.net/projects/ppm/