Plc

[kirem]

Does anyone work in the electricl/electronic control and automation industry?

I am looking for a reasonably priced PLC to control 10 outputs, mainly logic level and about 4 inputs, mainly measuring temperature and level.

Most of these will be temperature control routines. I would like the PLC to have PID algorithms.

Can anyone suggest any companies?

K

 

[kc_ksom]

My old man does these things,, I got no idea what they do, but im sure he does, how much you wanting to spend and where are you..
Casey

 

[dreamboat]

Have a look at some of the threads about using a computer to control your system.... you can get the control boards to get i/o for around $100, and the rest is in the programming. This is still a "one day" exercise for me, but that day is getting closer.
A PLC with analogue inputs to support temp probes, and probes to suit will be big $$. Then, the software to let you program will be another bunch of big $$. I had a look down this path when I had a free PLC in my posession, and gave it away as being too hard.



dreamboat

 

[roger mellie]

Howdy

Lurking here for quite a while - have a list of questions as long as my arm - will get to them in the course of time.

I am a PLC/SCADA engineer working in Process Control (indeed i do a bit of work for the beloved BOC (sorry no freebies) - What are your IO requirements - there are some cheapish systems on the market that have a bit of IO built into them - the hitch is to get one where the software to program them is freeware.

Siemens make a shoebox PLC called the 200 series that you can get with say 16 digital and 4 analog IO fairly cheaply. The programming software is pretty cheap for the 200 - based on the old Texas Instrument style of the 80's.

Have you looked on eBay? Sometimes you will find Allen Bradley SLC500 stuff going cheap. There are plenty of other manufacturers but as I dont have any software cant help you out there.

Jason

 

[kirem]

The PLC option is desirable as a simple solution. I have found a couple of PLCs with free software for about $200-$250.
What about these options;
http://www.oceancontrols.com.au/plc/fab_plc.htm
http://www.automationdirect.com.au/Welcome/plc/plca.html

I have looked at numerous solutions, including PC controlled. This option is nice as I could have promash and other brewing software all on the one PC. I am still thinking about this option.
There is a guy named Arnie who has a brewing system called HERMAN. This system is a PC controlled brewery. I have looked into modifing his code to suit my needs. http://users.tpg.com.au/adsl2y58/userfiles/html/about.htm

In a previous life I fixed electronics, so I have the skills to go the PC route, but I no longer have the time to write good code. But thinking about this has got the old techo fire burning again.

kc_ksom, I am in Mildura, but travel around a bit.

Jason or is it roger?, thanks for the info, I will have a look on ebay. Mandurah is a great part of the world.

 

[ArnieW]

Hi Kirem,

Thanks for the HERMAN plug

HERMAN is much more complex than most will want (or need). I'd suggest a good entry point is to program a PICAXE microcontroller. On my web site there is a design for a 'fridge controller' that can be put into service for HLT or Mash Tun, HERMS etc. I haven't tested it, but I've got someone's code for PID on a picaxe somewhere as well.

PLC would be somewhere in between (as far as complexity goes) but they have the advantage of being industrial strength.

Fridge Controller (PICAXE)

cheers, Arnie

 

[roger mellie]

Kirem

Its Jason - the Roger Mellie bit comes from an unsavoury nickname from Viz magazine - long story.

PC based control would be fine for your application - its generally frowned upon in PLC circles due to our old friend the blue screen of death - a tremedous random emergency stop device programmed free - thanks Mr Gates.

I dont know enough about the IO modules available for PC's to comment on that further with regards to price differential to a small PLC.

Exactly what are you trying to control? How many loops? If its just simple single temperature loop control then just the mini omron type temperature controllers would be ok - is there any sequencing to do? How automated are you trying to be? There are also some fixed loop controllers that were hideously expensive when they came out - Fischer Porter/Foxboro/Eurotherm that gave you some digital logic processing ability (8 channels from memory) - most of these got thrown away with the advent of modern PLC/DCS systems but you can pick them up on ebay occasionally.

There is an ebay item http://tinyurl.com/fx8b8 that would be perfect for any small automation product - shame it doesnt have any analog IO - thats the expensive part unfortunately.

Jason

 

[vlbaby]

kirem,
plc's is pretty expensive stuff if your looking for some serious PID controls and multiple analog input etc. I have worked a bit with seimens and allen bradely, and find the allen bradley stuff excellent. It would defeinelty do everything you want except the software alone for this will set you back around $2000.
On the other hand the little shoe box plc are great value, but will most likely lack PID type function and such. To be honest, these functions may not be neccessary if your smart with your programming.
Personally i'd go the pic option, or similar. Only thing is the programming will be a lot harder to handle for a first timer.

vl.

 

[Tony]

I also work with PLC/SCADA every day. even have an electrical engineering diploma in industrial electronics.

We use AB gear at my work and entry level Micrologix 1000 will set you back $700+ and then as stated above..... the software. I think the latest micrologix 1100 has an ethernet port too and will accept analogue modules but warm up your gold card.

There are lots of good little shoe box PLC's on the market, plug and play type units. Try contacting your local electrical parts distributor and asking them to see what they can source.

I think it was roger that sugested using omron tepm controllers. These are great reliable little bits of gear but PID controll is a bit over the top for a home brew rig in my opinion.

For true PID controll you will need not only analogue inputs from your temperature probes but analogue outputs to drive control valves to constantly regulate the flows and heats of the ststem..... otherwise its a waste of time.

The on/off omrons will do the job to within 0.1 deg and if you wont get better than that with PID. Actually your over and undershoot and settling times of a true PID system will probably drive you mad.

I have built a control panel using a couple of omron on/off controllers and i am confident they will do the job well. All i have to do is get time to build a stand and plumb it all up.

here is a link

http://www.aussiehomebrewer.com/forum/inde...61&hl=automated

cheers

PS. i will look into whats available if i get a chance tomorrow

 

[sintax69]

http://www.onetemp.com.au/PLC's.htm#FABdwnld

Try this mob they have some cheap and nasty plc etc

 

[Phrak]

I was chatting with a bloke at work the other day, telling him about all the fantastic automated brewing setups you blokes have, and he says to me that his sister works for Mitsubishi Automation & Control and that he had a few unused PLCs lying around his house that I could have if I wanted...

How could I turn an offer like that down? :beerbang:


Mitsubishi AL-10MR-A

100-240VAC, 4W max
Output 8A (Cos =1)

I was also given the serial interface for programming the unit, but no software.

Now what should/can I do with it? :unsure:

 

[roger mellie]

I was chatting with a bloke at work the other day, telling him about all the fantastic automated brewing setups you blokes have, and he says to me that his sister works for Mitsubishi Automation & Control and that he had a few unused PLCs lying around his house that I could have if I wanted...

How could I turn an offer like that down? :beerbang:
View attachment 14016

Mitsubishi AL-10MR-A

100-240VAC, 4W max
Output 8A (Cos =1)

I was also given the serial interface for programming the unit, but no software.

Now what should/can I do with it? :unsure:

Its dead easy Phrak - A PLC...

Inputs ---> Clever Stuff ---> Outputs

Thats all there is to it - the stuff that gives you the inputs and the stuff you drive with the outputs are pretty expensive but.

RM