Need some advice for PLC programming - beginner level - Page 1
Forum section: electronics / beginners

author: Chriss
author_rank: Frequent Contributor
timestamp: September 12, 2022, 08:14:20 pm
content: Hi!I'm not sure if this section is the right place to ask for help, but as a beginner, maybe it is.If not, pls. Admins move it to another more relevant part in this forum.I'm interested to learn PLC programming, I have electronic knowledge and uC programming too, but PLC is something new to me.Can somebody give me any advice what would be a good, maybe cheap solution to setup some development environment for a beginner like me?I mean, do I need a physical PLC or can I us a PLC simulator software on my computer to get in touch with this ?If a simulator program is enough for the very early stage of beginner, what free PLC simulator is worth to start with?Or any other suggestion I would really appreciate.Thank you.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 12, 2022, 10:06:29 pm
content: Automation Direct has their Productivity Suite which is quite good.https://www.automationdirect.com/support/software-downloadsClick on Programable Controllers then Productivity suite. Choose the older version 3.10.2.1The reason for this is the new version has a bug and when you use the simulator the simulate I/O doesn't work.

author: SmallCog
author_rank: Frequent Contributor
timestamp: September 12, 2022, 10:11:31 pm
content: This may be dejavu but I'm sure there was a similar thread a little while ago with a bunch of (what sounded like) good suggestionsI've only ever worked with one brand of gear, it's not cheap to get the hardware and either is the software license so I wont recommend it!Ladder is unlike anything else... Although it does feel a little bit like the original lego mindstorms with the drag and drop side of things...

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 14, 2022, 01:23:11 pm
content: Another software from Rockwell Automation (Allen Bradley) is the Connected Component Software which is free and included a simulator. I have never used it though.

author: Chriss
author_rank: Frequent Contributor
timestamp: September 19, 2022, 08:44:17 pm
content: I found this PLC interesting and maybe not so expensive, I hope it is ok gor a novice to jump in the PLC world.This setup would I buy to make my development board:Unitronics SM35-J-RA22 + V100-17-ET2.What you think about?Btw.: Why is that PLC's usind 24VDC instead 12VDC?Probably cos the extended range of the wiring cos the DCV?Or is there any other reason?

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 19, 2022, 11:57:35 pm
content: The Unitronics platforms are quite unique and every product family uses different software packages. The older stuff like the Samba you mentioned and Vision systems are quite old and dated. You’ll find them to be awkward and quite different from products like Rockwell and Siemens. If you plan to spend and money on the Unitronics, my recommendation would be to save your money. It’s a one of a kind product.It really depends upon two things. Were you live and what you intend to do with the knowledge gained. In todays world, PLC programming in ladder logic is archaic and quite unnecessary. Maintaining someone’s else’s ladder code is usually a nightmare on the best days.24vdc is the standard for industrial and process control industries.

author: Chriss
author_rank: Frequent Contributor
timestamp: September 20, 2022, 12:34:32 am
content: I living in a small town in Serbia nothing special place.My goal is to move forward from uC's to PLC's.I would like to learn PLC programming cos I'm I recognized ( maybe I'm wrong ) does I could maybe upscale my knowledge and learning a year or so and I could make some projects for the local industry.I made some projects finished anyway on agriculture watering systems, wood working industry nailing machines etc. but with uC's. Friends of mine who are use PLC's are telling me long time ago I should switch to PLC, but I never took the effort till now.This is my long story short..Any help I would really appreciate.I know, the best way to learn and practice is with real PLC, this is why I search a solution to make a small but powerful enough for learning on the bench.I found in my local store the mentioned PLC with that touch screen and LAN module for around 500eu brand new.I don't really know if that is worth the money but somewhere I must start...

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 20, 2022, 07:06:16 pm
content: If you live in Serbia I think either Siemens or B&R are more common. But with those the softwares are not free. In fact quite expensive very likely cost more than the computer you run them on.

author: Vtile
author_rank: Super Contributor
timestamp: September 20, 2022, 08:23:31 pm
content: Siemens, BR (no experience), Beckhoff, Mitsubishi.Ladder is for yankeesuse FBD, Graph or Structured text (Ada / obj. Pascal derivative).Honestly the best languages for low level logic control are:INSTRUCTION LIST (IL, ASM like)FUNCTION BLOCK DIAGRAM (FBD, Logic gate look a like)LADDER LOGIC (LD, relay logic diagram)Sequence control:SEQUENTIAL FUNCTION CHART (SFC / GRAPH, Grafset / petrinet / flowchart derivative)For fuzzy control implementations and math subroutines etc.:STRUCTURED TEXT (ST, Ada / obj. Pascal derivative)ST will go south fast with long nested IF-structures if you try to use it to complex finite state machines and complex logic.You need to be at least be capable to read all five. You can manage if you can use ladder and fbd fluently and read ST & GRAPH. You pro when you think in IL.The PLC is only a sratch in traditional sense, then there is variety of HMI and recipe systems. For small standalone machines you could use something like Siemens Logo! or Mitsubishi Alpha XL "programmable relays".Modern PLCs are (and actually have been for decades in capable hands ie. Siemens S5-135U/155U) far more than binary on/off controllers, the differences between process controllers (like Siemens PCS7) and PLCs are long time ago lost significance in many ways, but some still insist to draw the hard line.PLCs are rather simple to program, but PLC programming is only a fraction of work involved. System design/architecture, user interface implementation and design, process knowledge and ie. machinery safety to mention a few. The instrumentation & measurement then is another side of the programming literally, just like in uC, if you go outside boolean on/off controls.PS. As reply to unitronic question: Ie. Some vehicles/vessels do use 12V instead of 24V. For industry the 24Vdc is the standard solution for digital signals. The analog signals varies between (-10..)0..10V or 4..20mA depending industry sector. Be avare they do mention "C"-code something, for actual PLC code there is only those five languages that are somewhat portable between manufacturers so if you put a year of work creating your own programming do it all library with some vendor specific solution like "our C-code" you will be then locked to that vendor.

author: rooppoorali
author_rank: Regular Contributor
timestamp: September 21, 2022, 02:53:19 pm
content: Following are some links that may help you. You can take a look at the materials. These may help you to choose a low-cost but reliable PCB. And also give some ideas about projects.http://plccompare.com/cheap-plcs/https://www.theengineeringprojects.com/2015/01/introduction-to-plc.html

author: coromonadalix
author_rank: Super Contributor
timestamp: September 21, 2022, 05:07:07 pm
content: you could even start with arduinos stuff, you have open plc projectsit could give you some basic knowledge, sure the coding is a thing in itself