About a week? Come on; let's not be flip. He seems serious.
The answer is, "it depends." How much computer experience do you have? Even if you can reassemble and bench set a complete Foxboro 43AP and a Fisher Wizard from a giant box of unlabeled junk parts, no mean feat that would indicate years of controls experience, but don't know anything about this newfangled computer thingy then a PLC is going to take a while to learn. And if you already know how to drive around a computer pretty well, and already think pretty logically - quite likely since you already have some years of controls experience, then a PLC isn't really that complicated.
A PLC is just a computer, nothing more, nothing less. There's no magic; there's just a lot of it. It's not like the computers in Office Depot, but it's just a computer. And the programming language, unusually ladder logic, but increasingly more modern constructions, is specifically designed for industrial uses. You'd have a hard time writing a word processor to run on a PLC.
You obviously know which end of a computer to use, or you couldn't have posted the question. If you can get one in front of you to play with and you got the willingness to plow through the details, you can get comfortable enough to do basic troubleshooting on PLC controlled equipment in a few weeks. Most PLC classes, including the ones we offer (Allen-Bradley, not Twido), are one week long. If you show up knowing how to use a Multimeter, knowing how to drive a mouse, and have solid basic electrical skills, you'll leave Friday afternoon able to walk back in the plant Monday as a contributor to the team.
You won't get everything in a week, but you can get a tremendous amount in a structured environment designed to teach you by example. To get the same exposure working in a plant only finding things as they break could take you a year to five years to get the same exposure as a single class.
Of course, people also tend to remember the "boot in the teeth" lessons better than they remember Thursday morning's communications exercise. But if you'd had Thursday morning's exercise once, you'll have a lot easier time extracting the boot from you teeth when it does show up.
Question: "How long it will take, on average, to learn PLC (Twido)?"
Answer: That depends upon a lot of factors. If you have any previous experience doing any other type of programming, it will take less time than if you have none.
Most introductory PLC programming courses are 30 to 40 hours. At that point you should be able to write very simple programs, make simple modifications to existing ones, or readily read moderately complex existing programs. Developing beyond that point is a matter of aptitude.
Don't know Twido, but you'll probably be able to do basic programs within a week. The quality and organization of your work and your ability to use
more advanced techniques will continue to climb sharply through your next several good sized projects, but you will never stop learning new ways to do things, especially if you continue to get involved with new PLCs.
--
Steve Myres, PE
Automation Solutions
(480) 232-6862 Mobile
(480) 813-1145 Office
I wasn't being flip. I seriously expect the guy to be able to do basic relay-replacement type programs for small machines (not an unreasonable app for a Twido, if I understand it) in a week. Now, hopefully the one he does a year from now will be cleaner, better organized, more efficient, and done in less man hours than the one he writes next week, but I think he could actually do useful programming after a solid week of practice and reading.
If you already familiar with relay ladder logic you can learn to troubleshoot or write basic PLC ladder logic programs in a week or so.
It will take more time if you have to deal with analog signals and PID control.
It will take a few years to be comfortable writing large PLC programs, say anything over 1500 ladder rungs.
And as you add HMI and Alarm systems to your projects you will need more time to learn to do this.
As long as you deal with PLC's you will be on a learning curve.
The key to applying PLC's is not the PLC itself as it is only one of many automation tools. The real key to being an automation specialist learning how machines and process work to produce goods or products.
I agree with most of the above. It will help if you can go to a class. Most CEDs have some free classes now and then. Also if you know a programmer already who can answer questions that will sure help. With Allen Bradley PLC or Rockwell PLC, you have to have a cable to turn on the light, and a differnt cable to go to the bathroom. I have a bag full of AB cables, to program the many different modules.
But, one has to temper that with some pretty
ugly hacks that come from people who have
been programming PLCs for years. Talent
and aptitude do play a part. Being seriously
interested helps as well. I know why _some_
people make use of source protection. It's
FDTTW code.
The instruction set for most PLCs is pretty simple. If you have a basic understanding of boolean algebra, you can learn the syntax of most PLCs in a few days.
Whether you can apply it in a useful manner is something else. Much of what passes for "plc programming" these days is more akin to analysis development than straight programming.
Programming is pretty easy compared to figuring out just how the thing has to work, all the interlocks to the rest of the world and to pieces of itself, and interfacing both to the operator and other things around it.
Might be late in responding. I was in high school when this question was posted. Start learning PLC in 2009 in college and has been working in field since.
After 14 years, still learning PLC. I can program but keep learning better ways.
