Best brick PLC for learning

[PEERPSI 0]

My son, 15, in robotics and controls. As such I'm looking for an inexpensive brick PLC with digital and analog that uses either free software of affordable software.

Looking to do latter logic and simple analog scaling etc..

I've been working with AB products for decades and I'd like something from that family but the software, unless you like working with a patch over one eye, is too costly.

Considering an Arduino but I'd prefer simple ladder logic that is common in industry.

Any suggestions?

[pturmel 115]

The Automation Direct P541 with a combo I/O card is where I'd start.

[panic mode 237]

is that the "Productivity1000" series? if so the CPU should be P1-540 i think. it is modular but still very compact and software is free.

https://www.automationdirect.com/productivity/p1000

[pturmel 115]

Yes, that's what I meant.  (Obviously off the top of my head....  I have a couple in my office lab.)

[panic mode 237]

seem to be a very good value while retaining flexibility and having several common fieldbus options. looks very good...

[BobLfoot 281]

Slightly off-topic but Rockwell does participate in a number STEM activities and your local RA distributor and son's school might just be able to work an RA sponsored deal.

NO personal experience with such a thung, but the promo sounds good.

https://www.rockwellautomation.com/en-us/company/about-us/our-community/stem-education/stem-partners.html

As they all do. Caveat Emptor.

[pop29684 14]

You can get a Codesys license for Raspberry Pi. Last I checked it ran around $125 USD.

[qquazar 0]

I have my kids learning on Arduino

I think learning to program with structured text is way more important than ladder logic

I know ladder logic is used EVERYWHERE but it is really a bad way to learn programing.

[Crossbow 278]

On 11/8/2021 at 9:34 AM, qquazar said:

I have my kids learning on Arduino

I think learning to program with structured text is way more important than ladder logic

I know ladder logic is used EVERYWHERE but it is really a bad way to learn programing.

Ladder logic is NOT a bad way to learn programming.  It's a language designed for electricians, to look like an electrical schematic.  It serves a specific purpose, because when PLCs were invented, most of the time they were programmed and installed by the electricians, not by someone with a computer degree.  This language was developed to make learning programming easier for that target audience.

That being said, the best programs these days are a combination of both ladder and structured text.  There are many things that can be done easier in one language or the other, but there is absolutely nothing that cannot be done in both languages.  I still do Boolean logic and control of digital I/O in ladder, but use structured text for numeric data, comparisons, and mathematics.

[panic mode 237]

On 11/8/2021 at 10:34 AM, qquazar said:

I know ladder logic is used EVERYWHERE but it is really a bad way to learn programing.

everything has its uses.

learning anything (including programming) has to be done with a goal in mind since learning programming is time consuming. one should strive to reach the goal efficiently unless the journey of learning is the goal itself. one of the challenges with learning is how soon one get to apply learned skills, for example how much one has to invest before being employable or at least avoid frustration and loosing interest. you want to motivate them with series of milestones and successes. and teaching someone how to turn on an output or use timer in ladder is quicker than teaching someone how to do the same with Arduino. also programming PLCs in ladder makes you employable very quickly. 

learning to program MCUs is great and highly recommended but it is not for everyone. Arduino meant to make entry into MCU world simpler - and it succeeded. it lowered barrier of entry by making a lot of things simpler but still for plenty of people syntax and debugging options are a big turnoff.

also consider is actual area of application or final goal as not all programming is the same.

if you want to do databases or 3D graphics, time spent on Arduino would be nice though rather poor investment.

if you want to program PLCs, ladder is a great way to start as it is simple and quick to learn (low barrier).

databases are another rather low hanging fruit to be employable in rather short time (and build other skills like programming while having a job).

on the other hand Arduino skills are not exactly what employers specifically look for. for industrial automation position they sure would not mind seeing it on a resume as a bonus. for embedded engineer job positions, they would be likely to scoff or laugh at it - unless this is still just a bonus/footnote and not a core competency.

don't get me wrong, i encourage everyone to learn electronics and programming, and love Arduino. just offer another view. reason i mention this is because of own challenges. i tried and failed in convincing my son to give it a try - he just wasn't interested. <sigh>... i am happy for you that your kids are not like that. learning programming at any level is beneficial. i see programming today more as a literacy. it allows better use of tools we have and more and more tools are - computers. 

[Nilco1 0]

Does he want to learn C?

[STEM Apps 0]

Many opinions but if I heard you correctly, you want a controller a teenager can handle and learn to build on. I would recommend the Automation Direct Click PLC. Many will disagree but here's why I think it is a good choice.
Simple instruction set. Won't intimidate a new programmer. Ladder logic is easy to learn.
Free ladder logic software. The software is quite functional and easy to navigate. Having been in industrial controls for 45 years, 99% of industrial PLCs are ladder logic despite the building prejudice against it in the last 10 years or so. Download it even before you buy to see if you like it.
Supports motion control. Home, position and velocity move.
Has high speed IO - good for encoders.
Supports Modbus/TCP, Ethernet/IP, MQTT, RS232, RS485 - very good connectivity
If you go for the C2 series you can buy them with one or two internal slots to add your choice of IO cards and you can always add the external modules to keep building plus you can connect wirelessly as well as ethernet cable.