Test your knowledge on Allen Bradley PLC's

http://www.ronbeaufort.com/sample_lessons.htm

Scroll down a bit... there are 2 quizzes one for people like me (know very little) then one for the others

I will reply later with my results (I'm kind of slow)

Thanks Ron , I like test...

Congrats to Ron for these tests. Ron, you could make this test interactive. I have placed a free HTML testsystem on sourceforge, written in HTML and JavaScript. All you need to make up such a test is a text editor such as notepad. If you have Excel available, then you can make the test in an easier way. I'm still looking to find the time to make an OpenOffice version of this Excel file.

For people taking this test, don't be disappointed if your results aren't what you would expect. The questions are about issues on which there is some confusion in the field. I'm teaching how to use both SLC and CompactLogix, so I should know what this issues are all about. I won't spoil the fun by telling what the issues are, you should do the test and check the answers afterwards. It's sufficient to say that I scored 3 out of 3 on the 110 test and 5 out of 6 on the 210 test. I have an excuse for the not perfect score: I've never used a PLC5.

Kind regards,

I missed getting a job once because I could not define and explain P I D.

I do not like questions that say " Why won't it work". There is no will not.

rsdoran said:

I do not like questions that say " Why won't it work". There is no will not.

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It is much easier to prove things will not work than to prove they will.

Kind of my point

What is usually stated is "This will not work like this", does not mean it can not be fixed where it will work.

The issue is usually whether someone is willing to pay for what is needed to make it work, especially if expected to work properly.

a word of explanation ...

Greetings to all ...

first things first ... congratulations to jvcande ... that’s a much better score than I expect most people to make ...

actually I didn’t expect the “introduction” to my little quizzes to be posted on the public forum ... not that I mind - but these are meant to be “email quizzes” for (sssshhhhhh!) advertising purposes ... I sent a “beta” copy of them by email to some of my good friends for their opinions on the content ... one good friend apparently got caught up in the magic of the moment and quickly posted an invitation for everyone to share in the fun ... that was unexpected - but perfectly fine with me ... absolutely no harm done ...

as for the content ... these are meant to be (1) entertaining, (2) thought-provoking, and (3) educational - in that order ...

since I’ve gone into business for myself, I’ve had several friends offer to help by passing my name around ... some of these friends have suggested that it would be a good idea to have something to email out to prospective customers on a regular basis ... now personally I detest “spam” - or anything that remotely resembles spam ... so rather than writing a purely advertising mail-out, I decided to come up with a series of “PLC Quizzes” ... the idea is that I (or my friends) can email these to new contacts - and hopefully generate some increased exposure for my business ... notice that the Questions are meant to be emailed ... I prefer that the Answer files be accessed ONLY from the website ... it's free - and no registration, survey or visitor information is ever required ...

I’ve taken care to allow anyone who receives one of these quizzes to “opt out” of the program by just responding with “remove” in the email subject line ... I have no desire (and no reason) to send these to someone who doesn’t really want them ... but hopefully some recipients will find the material worth reading - and maybe even worth passing along to others ... if that exposure gets me a few extra clicks on my website then my objectives have been met ...

Where do I sign up to get these emails? That was great!

glad you liked it ... just send me an email with "PLC quiz" in the subject line - and ask to be put on the list ... I hope to do a new one every month or so ...

check the "contact us" section of the website for my email address ...

thanks ...

Peter Nachtwey said:

It is much easier to prove things will not work than to prove they will.

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Now theres a tricky statement.
'Work Correctly' can be such a subjective thing.

It may 'work correctly' how I THINK it ought to work but maybe the next guy has his own version of 'work correctly'.
Besides its virtually impossible to write code that cant be broken by an operator.
Thats what 'testing time' and 'commissioning time' is for isnt it ?

:nodi:

Ron's new quiz

Ron
Where do you come up with this stuff? I know it is from real world cases, but man you are the MAN! I can't wait to get my hands on the next set. A wise man (insert Ron Beaufort) has shown me the light to why a DC circuit hold up vs. an AC.

Thanks Ron! I think many have been waiting for the next quiz set, including myself. Please keep up the excellent work, it benefits us all.

Where do you come up with this stuff?

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most of it comes from my days as an inside tech support “telephone answer man” when I worked for an Allen-Bradley distributor ... the rest comes from my students’ “war stories” ...

Thanks Ron! I think many have been waiting for the next quiz set, including myself. Please keep up the excellent work, it benefits us all.

Click to expand...

the bad news is that I’m sort of behind on my “target” schedule for getting these out ... but the good news is that my business is picking up rather nicely - and that’s why I have less spare time to devote to things like this ... the next quiz in the “Go-To-Run” series should be out in a couple of weeks or so ...



thank you both for the kind compliments ...

Hey Ron....

I've been meaning to get back with you re:Training that we discussed awhile back. Been travelling like a madman and have very few days in the office. I did do my TI training and your insight on methodology helped alot. The hands on approach and the various tricks of the trade approach worked great...

Now, as to the reason for my reply here. For sh$$s and grins, I simulated your test about the fans with the Latch/Unlatch on a SLC 5/04. It does not behave according to your answer. This is on an older 5/04 so don't know if that makes a difference. But I put a single Unlatch statement on a input held true (NC pushbutton), and powered both the rack and I/O off a single supply. On dropping of the power, the output does not turn off due to continued scanning of the SLC 5/04 and loss of input as explained in your answers. This was the only rung of logic (I turned the fan on initially with an ON write in the data table). The Output was on a local chassis. Could there be differences because of firmware revision? The behavior was that the output turned off and the PLC powered down. On re-establishment of power, the Output came right back on with only the OTU as the single rung in the entire program.

Greetings Robert ...

I did do my TI training and your insight on methodology helped a lot. The hands on approach and the various tricks of the trade approach worked great...

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glad I was able to help ...

as for the quiz question, does the rough figure below accurately show the setup you used? ... if so, are you sure that the ladder was actually being scanned? ... if so, can you post the .RSS file? ...



I’ve highlighted the areas that I think you’re referring to ... if I’ve misunderstood your question (quite possible), please correct me ...







the idea behind the quiz question is that the 120VAC supply to the field inputs will suddenly drop out IMMEDIATELY - but the SLC continues to scan for a brief period ... this means that the normally-closed contacts of the switch in the field will “appear” to be an open circuit to the SLC-5/04 ... the XIO in the ladder will therefore be evaluated as TRUE - and the Unlatch instruction will write a ZERO to the output bit ...



you might also keep a close eye on the RUN LED on the processor as you turn the power off ... in all of the systems I’ve tested, the LED stays green for at least a half second or so - but the LED for the field input drops out IMMEDIATELY ...



I’m not doubting that your results are different - but I’d certainly like to know exactly what caused the difference ... there’s always more to learn ...



thanks for bringing this up for discussion ...

Ron,

Here's the file. Like I said, it's basic and the Unlatch is the only rung in the program and it is in Ladder 2. It certainly is being scanned. The only difference is that I didn't have a NC PB wired to the input, but a maintained selector switch turned to the ON position (same difference).

I did notice that the LED on the Output extinguished but then on re-apply of power, after the RUN light on the PLC came on, the Output came right back on. I did not notice the state of the Input. And just to clarify, the 1747 PS and the Input were wired directly off a single pigtail to an outlet. Pull the plug kills power to both.