rslogix 500 sequencer output

[ddrum24]

as i am still a little new to plcs, i need a little help. i have read the slc 500 instruction set to try and comprehend the sequencer output instruction. but i am missing something somewhere.

i am unclear on the whole thing especially the mask thing. i think if some one has a walk thru of one i could probably understand it.

one question is this. is there a seperate file for a ladder that is specific to that instuction only?

how do you tell it what the conditions are after a rung goes true to execute the instruction?

[Allen Nelson]

There's few questions that haven't been asked, and answered at length, on this site.

Use the button at the top of this page, and search for:

SQO

If you want to learn just about the Masking part, try:

SQO MASK

There's lots of useful info there, none of which bears re-repeating.

[rsdoran]

This may help: http://www.patchn.com/plc_adv_func.pdf

[mordred]

the thread "first program" has an example of SQO outputs. the RSS file is called general idea.rss. Essentially you create a record usually R6 on micrologic controllers then create a data table N7:* as your start point. You need to specify the length of the portion of the 255 32bit registers. contained under N7:* the masking is to tell the instruction which bits to look at. for example a mask of 000ffH
tells the instruction to look at the last 8 bits 0000 0000 1111 1111
the ones will be looked at but the 0's will not.(position). I will include an example here for you.

[Ron Beaufort]

Greetings ddrum24,

this little "music box" analogy of the SQO has helped a few people over the years:

previous post about SQO

and here is some more detail on the "mask" issue:

previous posts on masks

I'm not sure that I understand all of the questions you posted ... but maybe a look at the SQC would be a good idea ...

[ddrum24]

First off , thank you to all. Mr. Ron Beaufort the page you wrote on the SQO. man that is an amazing peice of work. i wished allen bradley would explain stuff in terms like that so dummys like me can learn it. i am begining to understand it pretty clear now, i think where i got confused was in the 16 bit word, i didnt know that was where the actual selection of the outputs was done.
the mask makes since now as well. but i am going to check the rest of the leads on here and try it out in a program and see how i do.
i will check every ones leads and sites and i have the stomach washer program. i think i may just about have it. TO EVERYONE THAT RESPONDED ABOVE THANK YOU!!!! beerchug

[mordred]

not to burst Ron's bubble the, music analogy has been used in the following manual PLCbook4_2.pdf. I've found it to be an excellent source on programming.

[mordred]

oops forgot to zip the pdf file?? hrmmm it appears to exceed the maximum size I tried twice to include the zip file anyone know the max size allowed ?plcbook

[Ron Beaufort]

Greetings mordred,

you might be surprised how hard it is to burst my bubble ... see if this is what you're after ... I found it with a Google search of the title you posted ...

link to the book in question

and actually I've never read this one ... so maybe Dr. Jack got the idea from my post? ...

[mordred]

wouldn't surprise me after all. All the real experts come here

[rsdoran]

Its funny noone thought to look at the link I posted except maybe ddrum. I posted the chapter that pertains to SQO and the aforementioned music box.

[DonsDaMan]

Your post predated his publication copyright, so I'd say it is more likely he got the idea from you... and you could not have gotten it from him unless you have a time machine.

I think of masks like those teacher's grading papers. You know the ones: They have a sheet of paper with holes cut in it. They lay it over your multiple choice test. If you didn't mark where the hole is (the mask), then your answer is wrong. If your "1" (marked answer) lines up with the teacher's "1" (the hole or mask), then the output is "1" (right answer). If they don't line up (you marked the wrong answer), or if there is no hole (teacher's answer sheet or mask has a 0), then the output is "0" (wrong answer, or more correctly "not a right answer" but sill a zero).

This explanation is much easier written on a white board and presented verbally.

[Ron Beaufort]

actually I was just kind of joking about the "who got there first" issue ... if you take a look at the second page of Dr. Jack's book you'll see that his first copyright was back in 1993 ... so maybe he did get there first after all ...

and funny you should mention the grading papers ... I've also heard some people use a "player piano" as an analogy for the sequencers ... but a LOT of people have never seen a player piano before so I don't use that one anymore ...

finally ... I know that a lot of people don't use sequencers ... for a lot of different reasons ... they're not my personal favorite things either ... but ... the fact remains that there ARE quite a few of the little beasts out there so it's a good idea to know how they work ... you don't always get a chance to choose your own battles ...

[ddrum24]

thanks guys, the extra postings are helping. i am downloading the plc book. it looks to be a good book from what i can see so far.

again many thanks to all, you guys dont know how much i appreciate you all taking time to put stuff on here because i wasnt smart enough to just search for a sequencer. and where i work everyone is very secretive and will not help me with nothing. so this is kind of a shock to me to actually get answers.