Cheap PLC recomendations Koyo CLICK? Others?

I need a cheap PLC for a project I am doing at home, (automated beer brewing). I will need about 12 DC outputs, 12 DC inputs. I also need about 6 analog inputs, prefer 4-20mA. I will have a couple of temperatur control loops that turn heating elements on and off through SSRs. I will also monitor levels and possibly flows. Start and stop 2 110v pumps and operate several ball valves.
I would really like to use the Koyo CLICK PLC because of the price and the free software, unfortunatley it does not have enough analog inputs, nor does it have a PID instruction. I believe I saw where someone wrote a PID for the CLICK but I am still short on analog inputs. Is it possible to add more analogs to the CLICK? Maybe over Modbus? Another option I thought of was wiring multiple analogs throughs relays so the program would select whichever signal was needed.Does anyone know of any other PLCs that might work? Anyway I want to stay under about $250 for the PLC, the software and any com. cables. I am an Allen Bradley guy, its all we use at work. I am not experienced with any thing you don't pay out the A?? for.

Thanks,
Greg

You can 'Click' on another Analog I/O card...

I would us the AD 260 series of PLC's...or to save some money, the 205 brick...

Would you care to make this a group effort??? :site:

I would be happy to kick in a 8 slot rack, a 260 processor and some 120 VAC I/O modules...I'm sure we can dig up a 12"+ touch screen, and I'm sure that the Smoke and Mirror Corp would contribute a collaboration of home brewers/drinkers to assist in writing the program...

:site:

I looked for an Analog I/O card and didn't see one anywhere, only digitals.

There is no analog expansion for the Click. Hopefully, A-D will offer analog expansion for it soon. Even their DL-05 won't do, because you won't be able to expand it enough to cover your needs (only 2 expansion slots). You would need to go with at least a DL-06.

Will you need to monitor all analog channels simultaneously? If not, maybe you could sequence the analog circuits as needed to the 2 channels on the Click via discrete I/O? You can stack up to 8 I/O modules on the Click. More than enough discrete I/O to do the switching. And those Click I/O modules are cheap!



-Eric

EDIT: I just re-read you post, and realized that you already thought of the analog switching!...

I have been mucking around with a Tri PLC, its a bit more expensive than a click but has 8 analog inputs built in.
http://www.tri-plc.com/f1616.htm

I think 250 USD will be hard to meet for 6 AI and everything else inclusive, even for low-cost brands.

Since you are an AB, guy and you can possibly borrow a programming PC from work for you home project (if you let your boss have a taste sample maybe), ebay seems to be a possibility. There is a lot of SLC500 stuff at very low prices out there.

Please Check For Delta PLC DVP14 SS and Analog Expansion card

Yes, I could use a SLC500 and program it at work,It would be hassle to check out a laptop to do any thing at home though. I have been looking at the Micrologix 1000, 1100 mainly because of the free RSLoogix Micro starter software. I can't find a used one cheep enough on Ebay though.

I saw that Tri-PLC website and have looked at it some. How easy is it to program?

Anyone have any experience with the Delta PLC from Taiwan? Whats the price range in US$

I bought one of these
http://cubloc.com/product/01_07.php
a few years ago to play with.
It is a touch screen with embedded PLC with 32 digital in, 32 digital out,
8 analog input channels and 6 analog outs.
Software is free, and there is a user forum on line with sample code

Might suit you.

Delta PLC Software is free to download on Delta Website.
Its Very easy to use and very compact but powerful instruction set.
Sorry i dont know the price ,but in india its very low cost.
DVP14ss 8di/6do can cost you 5000 rs indian currency.

Will you need to monitor all analog channels simultaneously? If not, maybe you could sequence the analog circuits as needed to the 2 channels on the Click via discrete I/O? You can stack up to 8 I/O modules on the Click. More than enough discrete I/O to do the switching. And those Click I/O modules are cheap!

Click to expand...

Very good point, Eric.

I think for beer brewing, it is very practical to sequence or multiplex the 2 analog channels to produce an effective 6 analog inputs. I have used the method before, and for certain applications, it works beautifully.

It would require about 6 more digital inputs to switch each of the 6 analog inputs to the available two on the Click. Each of 3 brewing inputs could be switched to 1 of the Click analog inputs, read for 2 seconds, the value stored internally, then the timer would cause the next input to be switched in. Because 3 could be switched to each A.I., it would only require 6 seconds to read all 6 into the Click memory. I doubt if a 6-second maximum delay would be a problem in beer brewing. Because each value is now stored in memory, but only a maximum of 6 seconds old, these values can be used as if they are real-time.

Liam, I checked out that Cubloc CuTouch and it looks pretty interesting. More than enough I/O for what I need. I like the built in HMI. More than I was wanting to spend, but probably cheeper than I can find a PLC and seperate HMI.

Anyone else tried this CuTouch?

If you are going to go in the embedded direction, Arduino is also a cool little unit:
http://arduino.cc/en/Main/ArduinoBoardUno

It doesn't have the built in HMI like Cublogic but the price is right. Also you can get them at RadioShack now.

You could build a web server into the arduino to control and monitor your microbrewery from your smartphone...good stuff!

Seewald said:

Liam, I checked out that Cubloc CuTouch and it looks pretty interesting. More than enough I/O for what I need. I like the built in HMI. More than I was wanting to spend, but probably cheeper than I can find a PLC and seperate HMI.

Anyone else tried this CuTouch?

Click to expand...

One of my former co-workers used one of those in his electric Miata project. He was more of a mechanic and had little to zero PLC experience so it was frustrating for him and I am not sure if he ever got it to do what he wanted. He talked about it in the break room and was lost when it came to writing VB code in conjunction with ladder logic to talk to his DC drive using modbus...He moved 100 miles away before I got the chance to see the little unit in person and help him out.

I have a little Click PLC that I have found to be no less than awesome...except for that pesky lack of analog...it's surprisingly powerful, fast and has lots of memory for a tiny little PLC.