Advice

Hi everyone.
I am a homebrewer (make my own beer) and I would like to use PLCs to control the heating/cooling of the wort (beer). The wort has to be heated to 170*f and then lowered to a couple different temperatures. I use a propane tank with a manual regulator to control the pressure of the propane used to heat the wort. Right now for the cooling process, I just rely on time for it to gradually decrease. I want to have a temperature sensor within the wort, which controls the output of the propane tank. I am looking for a new method for the cooling process. I'm not sure if I'm posting on the right forum, but it would be great to have everything controlled by computer. I am well versed in C programming, and I'm sure learning another programming language wont hurt. I read some of the other posts on this forum, and this doesnt look like such a hard task (compared).
I'm looking for a cost effective PLC controller system that can be controlled by my computer.
Thanks in advance,
PC

1'st of all, don't drink 2 much. Maybe you don't need any plc with PC.
It is possible find some PT100 I/O for Ethernet and much more I/O.
Check Ethernet I/O from the Internet.. cheers!

Thanks a lot!
I'm not much of a drinker myself, but I do enjoy making the brew! I will look for information on a PT100 I/O for ethernet. Thanks again!
PC

Here is what I think.

You sort of changed gears in your post as you went along, so probably the first thing to do is decide just what all you actually want to do.

First, since this is a home project, I am going to assume that the intial equipment cost is most important while trying to simply stick with what you already know is not.

Lets start by looking at each thing you told us:

I would like to use PLCs to control the heating/cooling of the wort (beer).

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If you only want to control temperature, you might want to stay away from both the PC and PLC based solution all together and opt for a stand-alone temperature controller instead. There are many on the market and some are pretty inexpensive, too. I have little doubt one of these can adequately handle your temperature control needs.

But you indicate there may be more than just that.

it would be great to have everything controlled by computer.

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If your desire is to incorporate a Personal Computer, there are a couple of ways this can be done. For instance, there are programs and interface cards that can turn a PC into a virtual PLC. I believe, however, that this will be your most expensive approach (and I am sure others will correct me if I am wrong). Another method would be to buy a PLC along with its required programming software and then some additional software that could turn your PC into an operator interface where it merely runs in a supervisory mode (also pretty expensive).

So you may not want to actually do it that way.

There is still hope, though.

I'm looking for a cost effective PLC controller system that can be controlled by my computer.

Click to expand...

Most of the time, you don't control a PLC with another device; the PLC itself is the controller. So I really doubt you want exactly what you have stated. Rather, I think you are asking for either a cost effective PLC with an appropriate interface or a cost effective PC based controller (the second of which, is probably an oxymoron in this case).

If you actually want to control more than just temperature (not knowing a thing about brewing, I would imagine you probably do) then a small brick-type PLC would probably be your best bet. You would then be able to get some switches and other stuff from some place like Radio Shack for control devices.

Going this route will also get you the best likelihood of good "free" support from those of us who frequent this site.

Hope this helps some.

Steve

Thanks Steve,
As you clearly pointed out, I'm not very familiar with PLCs. I will look into brick-type PLCs as an option. Temperature is the main concern. The mash needs to sit at certain temperatures for a desginated period of time. So time is also an issue. I will do more research tonight and post again tonight.
Thanks a lot for pointing me in the correct direction
and excuse my lack of PLC knowledge! :-D
PC

vedro: I would check out the MRO/Controls section on Ebay and see if you can locate a good temp/ process controller...most of these units will do a short process program that should fit the bill.
I too do some home brewing, some beers, but mostly wine and hard cider, but mainly let mother nature lead the way. There is something about having a 55 gal barrel of hard cider in the basement, all ready to bottle, and then having the joy of restarting the siphon for each new bottle...sure makes it hard to finish in one evening, even with some dedicated helpers.... beerchug
David