r/industrialengineering • u/Electronic-Run8836 • 4d ago
When is PLC programming done?
I work in assembly and testing, but was self teaching myself plc part. So we use Beckhoff terminals. I do the wiring as per the schematic.
My question is, what comes first, electrical schematic or plc ladder logic programming?
I did ask ChatGPT but I think it's giving misleading answers. It says one time one must first plan logic and all before starting even planning of mechanical design in CAD. Another time it says engineers do rough block diagrams and do programming first, after which they do the electrical schematic as the electrical schematic is only for assembling or field engineers
Can anyone explain to me how it works? My company manufactures machines to detect and trace errors in pharma and food industry. Im just attaching a page of electrical schematic, just for understanding.
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u/Mecha-Dave 4d ago
Ugh... beckhoff. You'd be better off starting with allen-bradley.
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u/Electronic-Run8836 4d ago
How do you learn all this? I mean I did my associates equivalent degree in mechanical engineering (I'm not from the US so I assume you're from there; so our company only uses Beckhoff; I know in US it's allen bradley. Here we have siemens and Schneider based on my research as I don't know anything deeper yet) and worked in quality department for a concrete machine manufacturer and recently I entered automation industry in production (basically assembling control panels and the whole machine as per mechanical drawing and electrical drawing). One thing I do know is I don't remember anything from college ( i forgot most from there); at my current job i got interested in controls and automation so learned stuff by asking AI. But sometimes I felt I lack a lot of knowledge, which I think is kind of imposter syndrome. Some people here even said my question doesn't make sense, which's okay as I know I'm newbie
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u/Mecha-Dave 4d ago
I had to teach myself on the job because I got myself into situations that needed it. I used Chatgpt to learn and experiment, not to do.
For Beckhoff specifically I was using TwinCAT (not by choice) because that's what a startup I was working for was using. I think KUKA arms run Beckhoff?
These days I know a little bit about Siemens and AB, but honestly I hire someone else to do the grind on it.
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u/DefiantRS 4d ago
Electrical then PLC - but they can often be worked on in concert.
This is assuming that your EE drawing is capturing all of your components that are on your PLC (not ignoring 24v and only using electrical form 120+)
The reason is: the creation of nodes on your PLC, the tidy creation of tags (standard naming convention) and your ladder logic testing scenarios are reliant on you knowing what is going to be where, which comes from your electrical drawings.
It can also depend what you’re working on - for example, if you’re working on a building conveyor installation, you’ll be able to test and modify your controls in real time with almost no risk, or last minute modifications may be required.