A Test

I was asked to find a test that could be given to perspective employees wanting to get into troubleshooting PLC's and Control I/O.

Does anyone know of any type of canned test? We use Allen Bradley PLC 5 with Rslogix5.

Thx... any help is appriciated!

I had one employer years ago that had a PLC5 and a light hooked up to an output. The test was to write a simple program to make the light blink. This quickly told whether or not they knew about rack addresss and programming. You would not believe how many applicants could not figure this out. FYI, I passed and got hired that day.

Marks employers test idea is all well and good for finding out if the applicant has a basic knowledge of the particular PLC family. But it won't necessarily help to identify potentially talented programmers with (or without) alternative PLC experience.

I think that what RSVIEWRULZ is looking for is a PLC aptitude test.
Unfortunately I've never heard of such a thing.
The only thing I would suggest is that if the prospective candidates have good PC programming knowledge (basic, c, java etc..) and you can tell that they're not bull****ing you, then there's a good chance that they'll have some aptitude.

I think you should ask question like How you start 10 motors in line
with delay between them with one timer.or if you want to complicate the question make it with different delay.still one timer.
In that kind of question you can check approach to PLCs programming.For any PLC.
If you need PLC5 programmer ask this question for PLC5.
In the way I understand it, if you have the basic knowledge for PLCs
you can program all of them after you learn the technique.
It hard to get good PLCs programer who can understand the all picture
of automation and not only the programming.

What other talents do your people need? Just PLC troubleshooting? If you are looking for an electrician that can swap motors, rebuilt starters, assemble MCCs, solder military connectors, that can also troubleshoot PLCs then why not require them to have taken a course on the subject. Anyone really interested in it will seek out education to get a foot in the door. When I was hired on all I had taken in 4th year was XIC, XIO, Timers, and Counters. I was up front about knowing practically nothing, but stressed I was very eager to learn. That's all it took. I wrote a test at the interview and showed them how little I really knew. Didn't know how many bits in a word, etc. Many interviewees in the past had bragged up what they knew and bombed the test. Who would you hire? Those types are not the safest people to be around in an industrial setting.

Or you could try something like this........

http://www.psy-test.com/Baptd.html

Antipathy said:

The only thing I would suggest is that if the prospective candidates have good PC programming knowledge (basic, c, java etc..) and you can tell that they're not bull****ing you, then there's a good chance that they'll have some aptitude.

Click to expand...

Well, in my experience, too much PC programming experience could be an impediment, not a blessing when applied to PLC programming. Not to mention that PC guys hardly ever have any idea about lots of other things, usually associated with controls.

When I was in position to test prospective PLC guys in my previous company, I usually asked them a couple of simple questions: a few from electrical engineering field and a few from PLC programming. Very simple ones (I felt that even the famous "one-bit toggle" could be too hard on a nervous job seeker - been on the other side of the table, you know).

Some of the favorites:
1. "How do you change the direction of rotation for a three-phase asynchronous motor?". If the answer is "by switching the leads", the following question is "Which ones?" This is where pure C++ guys usually fail...

2. "On an electrical drawing, there is a capacitor across a DC relay coil. What is the purpose of it being there?" If the answer is "for noise suppression", the question that follows is "what if instead of a capacitor, there was a diode?" This is where building electricians, the "counduit-bender" guys usually fail.

3. "You have a normally-open momentary pushbutton, a normally-closed momentary pushbutton and a motor starter. Please draw a sketch diagram of the motor starting circuit". I think a PLC guy should at least have heard about the concept of self-latching...

4. "Same set of hardware and a PLC. Now, the first (N.O.) button is connected to I1, the second (N.C.)is on I2, the starter coil is on output O1. Please draw a fragment of ladder logic with the same operation as the circuit above". Of course the critical thing here to watch is how confident the applicant is using an NO contact instruction for I2...

5. "A conveyor is driven by a motor; the motor contactor is connected to PLC output O1. There are two photoeyes: one at the conveyor entrance (input I1), the other is on the conveyor exit (input I2). Please draw a logic fragment that would start the motor when an object is seen at the conveyor entrance and stop the motor when it would reache the end - or would time out after 10 seconds". A simple latch rung with a timeout. Any programming style or PLC type the applicant feels familiar with.

That's all.

TESTING METHODS

Tests are (generally) used to screen out applicants so you don't waste your time interviewing those who don't meet some minimum knowledge/skill level. If you have a written job description, base your test on that description. In other words, if the job involves only discrete i/o, it's worthless (except as a tie breaker) to ask questions about pid loops.

If you really want "canned" take a look at the questions at the end of the downloads here: http://www.industrialtext.com/freestuff.htm

Enjoy!

RSVIEWRULZ said:

wanting to get into troubleshooting PLC's and Control I/O

Click to expand...

I took this to mean people looking for experience (ie trainees / apprentices) as opposed to already experienced programmers. And if this is the case, I still contend that PC programming ability can be representative of an aptitude for PLC programming, especially if they can demonstrate that they truly understand the basics of thier chosen language.

-Anthony

In the past 3-4 years, I was asked to interview number of people.
Personally I don't like ****y guys who think they 'know it all',
I like much better fresh kids willing to work hard and build their
experience on what they learned in school (that's the way I did, do
and always will).

To make things more simple, I've created small list of SIMPLE
questions for just about anything our candidates would say
they know.

We are smaller company, so if you work for us you better know more
than one thing...(Ohms Law, PLCs, HMIs, Networking, VB, Database,
CAD, CEC, Safety, Motion, sensors etc.).
It is shocking how many have no clue about most basic things.

For example, just few weeks ago, there was a guy who says he is
an EE with Masters degree from XYZ and although didn't have ANY
experience in anything else, he was a professional programmer.
I didn't like the guy on first sight, I didn't like his long
greasy hair, big shot lazy posture with one leg over another
and cigaret in his hand, masive gold rings on just about any finger
(or are they really gold?), bad breath and he could really learn
that there are stores in town that do sell deo and shampoo
(I was about to be the one to inform him but wasn't sure if this
would be considered harasment...).

So ALL he did in past 12 years is program AB PLCs for major
automotive plant, single handedly troubleshoot the most complex
equipment etc. My boss was really interested to hire him.
I brought him one limit sw. (AB 802T-AP) and one proxy switch
(Omron E2E). He couldn't recognize any of them (my WIFE can do that!).
So I ask him to calculate series resistor for LED to be powered
from 24V circuit. I help him draw the circuit, specify source
to be 24V and correct polarity, LED has 2V drop and I wanted
current of 22mA (just to make it easy to calculate in head).
I even give him calculator... Not a killer for an electrical engineer, don't you think?
He spends 15min writting something elaborate and then asks for
more info. He says if he sees resistor he would know to pick the
righr one. All right, I bring him three resistors and one capacitor
(one resistor with correct resistance and power rating) and I
even give him digital multimeter so he can measure them all and
at least guess result.
Guess what? He didn't know how to use multimeter (so much of a
troubleshooter). Interestingly, my boss pulls me to side and suggest
to hire him anyway so "he can start one or two projects" and
I would have to finish them (yeah right, just what I needed...!).
I say no, the guy hears it and jumps yelling that he is
a programmer and wants to prove his proficiency by answering ANY
posssible question about AB PLCs (before ControlLogix off course).
No problem, so I ask him answer ONE thing correctly:
- what is S:1/15 or
- what is TON or
- what is N7.
He was scratching his head for 10 minutes and his face was changing colors (at that moment I did enjoy it, I don't get that oft to just
sit and do nothing...).
Finally he erupted in rage saying that he is an experienced programmer
and that he wouldn't work with me even if we wanted. (YESSS!!!! I already tought hed never say that... ).

You may want to look at RAMSAY tests

They are used by many plants for entry level, intermediate and advanced in electrical, electronics, plc or mechanical.
http://www.ramsaycorp.com/

panic mode:
The led would obviously leave 22v across the resistor so to obtain 22ma it would be 1000 ohm.
S:1/15 First Pass
TON Timer On Delay
N7 Default Integer file
The AB 805T I believe is about 4 inches long and 2 inches square that the "arm" can be adjusted to different positions, the head can also be rotated and its dual acting..ie the switch can work from either direction. The T designates it as oiltight.
That specific prox I dont know but since you grabbed off the shelf I will assume its probably a barrel type...possibly capable of dual action also..ie NO or NC.

Do I get the job?

Oh I forgot, you dont like ****y guys with an attitude.

I want to thanks everyone for the great input!

With the webs posted I am sure I will find enough to get a test going and in the direction needed.

rsdoran.... Nope you dont get the job... I need a resume'

Thanks Everyone

Ron, sure you'd be hired...

The AB 802T I believe is about 4 inches long and 2 inches square that the "arm" can be adjusted to different positions, the head can also be rotated and its dual acting..ie the switch can work from either direction. The T designates it as oiltight.

Click to expand...

I didn't expect him to tell the specs. He couldn't tell the limit sw was a limit sw. and proxy (it was 18mm barrel) was a prox. He probably never saw one but boldly claimed industrial experience and top notch troubleshooting skill.
What happened to honesty?

I am not sure you can blame him for trying to bluff his way into a job that he wasnt skilled at, he may have been an astute person that in the past had to learn as he went on every job.

With the economy as is and companies laying off, closing down, reorganizing etc, many people are looking for work that have been fairly successful in the past. Some, like your guy, have never been without work and the prolong period they are off has probably caused financial problems. Normally that also creates other problems in family.

We got a saying in the US:
If you cant dazzle them with your brilliance
Then baffle them with your bullsh*t

Re: You may want to look at RAMSAY tests

rsdoran said:

They are used by many plants for entry level, intermediate and advanced in electrical, electronics, plc or mechanical.
http://www.ramsaycorp.com/

Click to expand...

I'd be pretty hesitant to use these tests.
Even their sample questions have some pretty blaring errors.
See the resistor color code question on that page to see what I mean.

My 2 cents

I do the hiring. Of course, I own the company.

My single most important factor is this one.

IF I can get my hand on a young guy which was raised in rural area (preferably a farm) whit good knowledge of electronics... HE'S GOT THE JOB!

I have found that this profile is the perfect one.

They have done hands-on work (with there father).
They are not afraid to get dirty.
They have this humility to often absent from big city boys.
They think outside the box(a necessity for remote area solution finding)

See, IMHO what you are is more important than what you know.

Unless I need him to start on the night shift next monday then I'll go for the old-bastardz