I am an electronic embedded software engineer with no control engineering experience. I want to produce a process control system for a simple raw materials batching plant for our home business.

I know what ladder diagrams etc are and see no reason why I cant pick it up. Software is software. But I would like a kick start. Basically Id like to know if there is a PLC kit I could start with that will include everything I need to program the PLC as well.

Also I will need a front end (MMI) user control for my control system to input and store recipes (different combination of raw materials ) and then also produce a desired amount of batches.

Are PLCs gone out of fashion yet perhaps there is a better solution.

 

PLCs will outlast most of us. The glacial pace of progress in automation has some advantages. It will accelerate one we get rid of the Microsoft millstone. But I digress. I don't know of any kits for PLCs, I have board designs for a do it yourself design but they haven't been built or tested due to lack of funding. But, if your needs are modest, you can probably get commercial product cheaper than a kit would be, due to efficiencies of scale and volume. I suggest you look at the Click from Automation Direct (Koyo) the PLCs start at $69 and the software is free. It is a slice product, that is, you can add modules as you need them. And Koyo has been in the game longer than almost anyone except Modicon and has made PLCs for many famous brands. Their other lines are worth looking at as well. Or you can do PC control with the MAT tools or MBlogic or the like but the cost of suitable IO is discouraging and it should have a dedicated PC and run anything other than Windows. This also puts quite a bit more load on a one man operation. There are dozens of low cost microcontrollers that can be used as well, but these too have IO issues and require a lot of learning to produce reliable, versatile control. These are closest to a PLC from scratch, but you need to come up with your own low level software. Unless you want to be in the controls business, the PLCs probably require the least effort and are proven. I'm normally much bigger on the DIY side, but I am in the controls business and I'm trying to see from your viewpoint and it's too easy for controlling your "plant" to take too much time away from running it. Just as "business" takes too much of my time from the techie stuff.

Regards
cww

 

PLCs are still in. What you use depends upon your application. You need to provide more information for help in that.

For a small batch operation with on-off control, one of the microPLCs or shoebox PLC should do just fine (Direct LOGIC DL05, Modicon M340 or Compact 984, Allen-Bradley MicroLogix or SLC 500, etc.). If you have some continuous control, things get a bit more complicated and a small PLC may not be the right solution as depending on the size and complexity, a different solution may be warranted. There are also PC based controllers like LabVIEW (http://en.wikipedia.org/wiki/LabVIEW) or PACs (http://www.automation.com/portals/programmable-automation-controller-pac).

Here is a PLC website that may be useful.

http://www.plcs.net/

For reasonably priced PLC stuff and HMIs, look into:

http://www.automationdirect.com/adc/Home/Home;jsessionid=5e30c143dffbd361a43762271c2d562c3c44


William (Bill) L. Mostia, Jr. PE
Sr. Consultant
SIS-TECH Solutions, LP

Any information is provided on Caveat Emptor basis.

 

Check http://www.tekitech.com (Fatek USA) for compact sized PLC. They have 3.5" color PanelView as HMI. Instruction set is very similar to Modicon PLCs and wit a lot of flexibility of expanding the I/Os. It has communication server (Free) for PC to read/write PLC data. Editing software is free. If you like to try it before buy it, go to http://www.fatek.com download section for the simulator and user manuals. That should be a good start without chipping out a dime. The price range is in the middle. Not expansive but not in sub $100.

 

If you are not a fan of ladder logic and prefer more high level languages, look at http://www.beckhoff.com/english/default.htm or http://emea.kontron.com/industries/industrial+automation/embedded+ipc/
both are programed in variants of CodeSys or even regular PC languages.