STUDENTS ATTENTION -- from a student

I just saw a post from some clown asking for a traffic light program.
Basically what he is saying is do my work for me and do it for free.

I am a student and I understand the issues of being a student. I have an AA BS and MS so I been thru the school hoops. I am now going to school for PLC knowledge.

Here is the way it is and how to get help from these guys.
They will drown you in knowledge and help if you:
1. DO NOT ask them to do it for you.
2. Come up with a clear question.
3. Have some kind of proposal or diagram to show what you are thinking.
4. If you have no idea of whare to start ask them to send you to reference materials -- AFTER you have tried the school library and public libraries AND tell them you tried the libraries.

It does not matter how wrong you are if they see you trying.

Dan Bentler
Graduate of
Navy Nuclear Power
Mt Hood Community College
University of Washington (the BS and MS)

Dan,

Well put!!!!! Maybe some of them will read this before just asking for it..

On behalf of many...

DAN:

I can't speak for every member of this community, but I speak for many when I say

Thank You!

regards.....casey

Martin beat me by seconds.

Re: On behalf of many...

kc9ih said:

Martin beat me by seconds.

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Casey,

You know seconds matter in this age of the 8 second traffic light. HA-HA

Sorry Dan for jumping on your thread just couldn't resist that one.

Students

Martin and Casey

I see a lot of this irritation with students here. Some is justified - that clown with the traffic light was a classic.

I really think a message to them should be right at the top so they know what to do. Melore can keep mine at the top. Students cannot cry because I am one.

In my 20 years of safety work I came across operations and machines I knew nothing about. I found if I asked the operator what the machine did and explained why I wanted AND NEEDED to know I generally got an answer - sometimes hours worth.

I have asked a couple questions already and will ask more. Some will be really dumb BUT if I knew I would not ask.

Today I just finished setting up an AB 1000 to test NC and NO (Stop / start) configured as XIO AND XIC to see what happens. As mentioned in other post (with a Siemens) and with no imputs I got an output. That scared me showed my ignorance and is why I am going to school. I still do not instinctively understand XIC and XIO but that will be a matter of practice. I DO KNOW they can be real dangerous when wrongly used -- as usual (being a good electrician) I will always test my work before declaring it good.

Dan
Dan

Re: Students

leitmotif said:

Today I just finished setting up an AB 1000 to test NC and NO (Stop / start) configured as XIO AND XIC to see what happens. As mentioned in other post (with a Siemens) and with no imputs I got an output. That scared me showed my ignorance and is why I am going to school. I still do not instinctively understand XIC and XIO but that will be a matter of practice. I DO KNOW they can be real dangerous when wrongly used -- as usual (being a good electrician) I will always test my work before declaring it good.

Dan
Dan

Click to expand...

Keep at it, you'll get the hang of it.

Safety always, last program I wrote, now get this, it's a automated glass cleaning sink in our glass welding room. 117 gallons DI water 10.7 gallons HF (hydrifloric acid(spelling??)) Talk about being worried HF is some bad stuff. But before it was put in operation I made sure they let me test everything with just DI. Works great, just a lot of wasted HF.


I guess this ex squid needs to get back to school too one of these days, only been saying that for the last 9 years.

Greetings Dan,

regarding your statement:

I still do not instinctively understand XIC and XIO ...

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maybe the “big picture” explanation in this post will help ... secret handshake: when people don’t fully understand the XIC and XIO concepts, it’s generally because they don’t understand the underlying concept of the PLC processor’s “scan cycle” ...

Ah, Dan, the days of NPS at Orlando (1979-80)!

I, too appreciate your post. We been needing it! It's the same thing we've been saying for a while now, but hopefully it will carry greater impact being authored by a student.

Best of Luck to you and welcome.

Re: Students

leitmotif said:

that clown with the traffic light was a classic.

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There have been multiple clowns.

First note that XIO and XIC are AB nomenclature, in general they are just contacts that represent an on or off condition. DO NOT try to think of them as NO or NC contacts/switches.

This contact --| |-- will look for a input to be ON..ie there is flow thru the device to the input.
This contact --|/|-- will look for the input to be off, no input signal.

Dan,

I salute you. You're the kind of student I like to teach. Unfortunately, you're part of a minority. With this thread you've earned my respect.

Kind regards,

They still exist..........student(s) with common sense.
And I was thinking they where extinct

Good luck in your studies, that we (I) may help you a lot !

Re: Students

leitmotif said:

...I still do not instinctively understand XIC and XIO but that will be a matter of practice...

Click to expand...

This is definitly not a user friendly way of representing the world outside the PLC. The trouble you have with these simbols is relevant and MANY of us have the same problem.

When I switch from AB to Mitsu to Siemens to Modicon to ... It takes me a few momment to get back to speed with them XIC XIO ...

For me its just not natural.

Its the O and the C the problem. I'd rather have XIZ or XIA ... the Open and Close is playing tricks with the mind ...

Actually, it seems that the students are getting better (or our reputation for how we treat them continues to grow).

In the last month, we've had no less than 4 traffic light requests (which sadly, is a record).

But.....
dpatto01 actually posted code (badly written), and asked for comments. He got lots of help.
hoodedrat described his code, and asked for tips on modifying it. He got some help.
ajfril actually posted workable code, and wanted to make it better.
Only rcmarket asked for code without first showing his work. Naturally, he got the standard treatment. (Although he claims to have found the answer on this site. So I guess we helped after all.)

3 out of 4 showing their work - that's also a record! For a year, let alone a month!

And here we have another one who understands what we're about. Amazing.

Sadly, the flop-flip problem isn't going so well. Two so far this year, and neither showed work (although I believe they both recieved a solution). Not a record, but high.

My point is that there is signs of intelligent life out in studentland. And those who post with some effort at showing what they know will continue to recieve help.

Allen Nelson said:

Sadly, the flop-flip problem isn't going so well. Two so far this year, and neither showed work (although I believe they both recieved a solution). Not a record, but high.

Click to expand...

Now I'm wondering about the stats of the "Unitary, Modular, or Rack mounted" question...