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  • Seeking advice on choosing a PLC

    Back a few years ago, I wanted to learn how to program PLC's I started with one of those training kits that gives you a basic Micrologix PLC unit with buttons and lights. It was a good starting point but I found it limiting since real world machines have variables that have to be accounted for, say for example, a sluggish cylinder. So I came up with an unusual approach to the problem, and it was also at a time with my old job, the plant was shutting down so I was able to scavenge parts from machines that were being scrapped. I decided to build a model railroad layout and use a PLC to control the movement of the trains. I was able to get a larger Micrologix 1000 PLC for more inputs and outputs and have had some success with programming some routines. I then purchased a Cmore HMI panel and started writing screens for it. My eventual plan is I have a around the wall layout in my living room and it would be cool to have the final product controlling the trains with a HMI panel and such. I posted my progress on my website here:

    https://www.nepaview.com/model-train-plc-project.html

    I have run into several limitations with my current PLC. It has no analog I/O so there is no way to control or sense the speed the trains are running. It also cannot sense the switch positions since I have run out of inputs. This PLC cannot be expanded and it is a discontinued item. I already have had to repair it twice for failed relays, so this is another reason to move away from this unit. The memory is also limited on this unit and I am also near filling the capacity of the PLC. So ample memory for the program is also needed. I would think newer units have more memory anyway.

    Ive been looking at replacing it with an AutomationDirect PLC. I recently have used a Click PLC to design a project at work. (picture attached) Although for a larger program, the software is a bit cumbersome and the PLC has limited instructions. Plus the Click software does not support simulation of programs, so for the model train project, I don't think click is a good choice. For the project at work, it was only like 14 rungs of code so the Click was a good choice for this project.

    I have done on the site the configuration tool with both the Do-More BRX and productivity 1000 series PLC's I didn't yet do that with the Do-More PLC. What I am asking is for those who use these other PLC's is the software, I don't care if its a paid program verses free. Based on the configuration tools, the cost difference between choosing a PLC is not much so I am more interested in which PLC has the better software package. The main feature I need is being able to simulate a program. This way I can write some code and test it to see how it works (or if it doesn't work ) before sending it to the PLC unit. (RSLogix has an emulation module that simulates a PLC, you just "upload" your program to the simulator)

    So I am asking for suggestions as to what would be a good choice for this project?

    Mike
    Attached Files


  • #2
    I like the BRX but i prefer the way it programs compared to the tag system the productivity uses. Both are free to download off the AD site so I'd download them both and do a few simple programs and see what you prefer. Do More i know has a simulator built into the software, I'm not sure about the productivity line. We have 2 productivity that came from a vendor and have not had to do anything with it except we downloaded the program so if we have to replace the plc we can restore it. Both are going to be way cheaper then AB.

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    • #3
      BRX has a good simulator, Productivity does not have one.

      If you go with the 36IO BRX unit you can also get it with 4 analog inputs built in that work very well.

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      • #4
        Do-more Designer is free and the Simulator is free. It's the only PLC line ADC sells that has a windows-based PLC simulator. Hence, you can "kick the tires" without spending a dime!
        There are 10 kinds of people in this world, those who know binary, and those who do not.

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        • #5
          Originally posted by franji1 View Post
          Do-more Designer is free and the Simulator is free. It's the only PLC line ADC sells that has a windows-based PLC simulator. Hence, you can "kick the tires" without spending a dime!
          Is the simulator still limited to a small handful of I/O or has that changed?. IIRC, there are 8in and 8out and a few analog IO - and maybe a sprinkling of memory bits.

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          • #6
            Originally posted by kewakl View Post

            Is the simulator still limited to a small handful of I/O or has that changed?. IIRC, there are 8in and 8out and a few analog IO - and maybe a sprinkling of memory bits.
            The Sim isn't I/O limited, only buttons on the dialog. Any I/O point can be used and changed by code or Data View.

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            • #7
              Originally posted by BobO View Post

              The Sim isn't I/O limited, only buttons on the dialog. Any I/O point can be used and changed by code or Data View.
              Yeah, that is what I remember. Thanks for clearing up that lack of understanding!

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              • #8
                Id go after the 36I/O Brx.. Oh wait.. I did!! I was facing an Unknown Task.. With Unknown Requirements, and a 2 Month HARD Deadline for completion of the Project.. I bailed from my Old Standby of the 260 PLC and went to the BRX.. it has E-Net and ModBuss Via E-Net Native.. It took a while for me to get the feel of the Software.. and the native I/O was plenty.. The Ability to Add I/O has turned out to be a Plus in this years Incarnation of the New and Improved Project ( I hate Marketing Guys )... snapping to the side, and then all of my documents reside in the PLC, so my Scatter Brain did not have to keep track of all the Latest stuff, and if my 'Helper' changed it..

                I'm now looking for excuses to replace the Old 260's with the Brx..

                Brx..Brx..Brx..Brx..Brx..

                Cap



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                • #9
                  +1

                  Originally posted by Cap View Post
                  Id go after the 36I/O Brx.. Oh wait.. I did!! I was facing an Unknown Task.. With Unknown Requirements, and a 2 Month HARD Deadline for completion of the Project.. I bailed from my Old Standby of the 260 PLC and went to the BRX.. it has E-Net and ModBuss Via E-Net Native.. It took a while for me to get the feel of the Software.. and the native I/O was plenty.. The Ability to Add I/O has turned out to be a Plus in this years Incarnation of the New and Improved Project ( I hate Marketing Guys )... snapping to the side, and then all of my documents reside in the PLC, so my Scatter Brain did not have to keep track of all the Latest stuff, and if my 'Helper' changed it..

                  I'm now looking for excuses to replace the Old 260's with the Brx..

                  Brx..Brx..Brx..Brx..Brx..

                  Cap


                  This is a great PLC! Communication / Expandability / Documentation

                  Garry

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                  • #10
                    Originally posted by MikeN View Post
                    BRX has a good simulator, Productivity does not have one.

                    If you go with the 36IO BRX unit you can also get it with 4 analog inputs built in that work very well.
                    The unit I looked at and configured is this one. Don't need the ethernet as the Cmore panel I have doesn't have it. It includes 2 analog outputs which is what I actually want so I can control the throttle of the trains. I found a schematic of the Lionel transformer online so I know where I need to tap in to control speed.

                    I will have to download the software and try it out. Thanks for the feedback!

                    Mike
                    Attached Files

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                    • #11
                      OK.. you don't 'Need' E-Net.. It's great to have.. Remote I/O using E-Net Modbus is great.. fast and easy to install..

                      For my Project, I needed to Control and Read, 12 Air Cylinder on a Rotating Carousel.. the E-Net ModBus Worked Great for the Sensing of the Cylinder Limit Switches, and the Native E-Net Comms worked for the E-Net Air Cylinder Sol Valves ( 12 of them ).. all through 4 comm lines and two Power Lines.. and all this on a Rotating Carousel, fed with a Rotary Electrical and Air Joint..

                      It could have been done through Rs434 Serial.. but not as fast and easy..

                      Just Saying..

                      Cap

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                      • #12
                        I use the built in ethernet more often for connecting to a computer networking with internet access and email logs I record. Also handy for emailing yourself an alert that you set up. For instance if there is an error with a train and you want to know about it when you arent around you can email that alert and a log of the tags/memory addresses that list the problem

                        It would be fun to play around with anyway whether you *need* it or not.

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                        • #13
                          Perhaps in the future since this BRX does come with Ethernet I will use it for something. Right now I need more I/O then what the Micrologix has since I have to make assumptions on the layout. One big example is when the program throws the switches, it has no way to sense a switch jam. I modified this solid state interface card to read 5 volts instead of 24 volts to tap into the LED of the switch. When the switch is set to the throughway, the LED is green. When the switch is thrown to the turnout, it changes to red. I don't have any more inputs (I need six) to sense the switch position. If a switch jams, the LED is off.

                          https://www.nepaview.com/uploads/5/7...71836_orig.jpg

                          https://www.nepaview.com/uploads/5/7...71837_orig.jpg

                          As discussed above, the ML1000 has no analog ability and I want to be able to control the speed of the trains.

                          Mike

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