Conveyor/Machine Sync Dilemma

So we have a packaging line that's going thru a major overhaul. It's currently controlled by a 1769 L30 Controller and a PVP HMI. We're replacing the PVP and re-doing the entire HMI program and we're going to wipe the original Rslogix program with a new one because of the changes and it's too complicated and in Italian.
Bottom line the only issue I'm having is trying to duplicate the speed sequence between our can filler and the conveyor that pulls the can from the filler; Currently it uses an analog output from the filler (filler speed ref from drive) as an analog input into the conveyor controller AI module, scales it and then correlates that speed with the conveyor speed so they match throughout speed changes (cans per minute).

I know that over a certain number (10000) the conveyor runs at 8200 or 82 Hz and at idle it registers around 5400 because even though the EU coming in is 13500 it's set at 0-10000 to 0-100 scaling.
The logic is a bunch of cpt instructions that go everywhere incluing a JSR/SBR and RET. I cannot find the actual method of control for the speed reference sent to the conveyor reference but it changes when you decrease the cans per minute speed and also with taller cans we slow the machine down and therefore the conveyor needs to slow proportionately.
I need an easier way to make these speeds correlate. By taking the analog in and developing a reasonable analog out--to me it almost seems as if a PID instructions might even work.
Any questions just shoot.

TIA

toddp65 said:

... and it's too complicated and in Italian. ...

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:clenched_teeth:

Must. Not. Respond. To. Every. Straightline.

drbitboy said:

:clenched_teeth:

Must. Not. Respond. To. Every. Straightline.

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why the clenched teeth?

toddp65 said:

Any questions just shoot.

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Since you ask, ...

toddp65 said:

Bottom line the only issue I'm having is trying to duplicate the speed sequence between our can filler and the conveyor that pulls the can from the filler;

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By "speed sequence," do you mean the code that uses the can filler speed input to calculate the conveyor speed output?

toddp65 said:

Currently it uses an analog output from the filler (filler speed ref from drive) as an analog input into the conveyor controller AI module, scales it and then correlates that speed with the conveyor speed so they match throughout speed changes (cans per minute).

Click to expand...

By "correlates that speed" do you again mean that the code uses the filler speed to calculate the conveyor speed output?

Or is the filler speed calculated as an output based on a conveyor speed input and/or the cans per minute?

How does "cans per minute" factor into the calculation? Is "cans per minute" measured value, or is it set from the HMI, or does it come from another source?

toddp65 said:

I know that over a certain number (10000) the conveyor runs at 8200 or 82 Hz and at idle it registers around 5400 because even though the EU coming in is 13500 it's set at 0-10000 to 0-100 scaling.

Click to expand...

That's a bunch of numbers with very few units attached. It sounds like 8200, 5400, and maybe 13500 are 100 times speed values in Hz (82,54,135), is that correct? Which of those numbers relate to can filler speed and which relate to conveyor speed?

What are the units of the "certain number (10000)?"
When you say "over a certain number (10000)," does that mean an event where some value (of unknown units) exceeds 10000?

Which, if any, of those numbers is used as an input to the [0-10000:0-100] scaling?

What are the units on either side of the scaling (0-10000 and -100)?

toddp65 said:

The logic is a bunch of cpt ... I cannot find the actual method of control for the speed reference sent to the conveyor reference

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Would it be possible to post the existing code?

toddp65 said:

but it changes when you decrease the cans per minute speed

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Is this referring to the current behavior of the existing code, and the desired behavior of the new code that will replace the existing code?

This implies again that "cans per minute" is used in the calculation of conveyor speed output; is that correct?

toddp65 said:

and also with taller cans we slow the machine down and therefore the conveyor needs to slow proportionately.

Click to expand...

Is can height (or just a short/tall boolean) a parameter used in the code that calculates conveyor speed output?

If not, then how do "we slow the machine down," and by how much, when taller cans are being filled?

Ok, wow--
Thanks for the detailed response to my response.
I guess its easier to put an introductory question with limited info that describes the dilemma and then elaborate when someone takes a bite.

You ask great questions and I'm basically going to toss in the remedy I came up with that'll get me to where I need.
A simple AOI used in the original program (they called it analog read but basically a SCP) and the input would be the range of the EU for the filler speed range (0-13500 est) and the scaled range being the desired conveyor speed out to the drive speed reference (0-8200) which is being used now. With a test Analog read in the current running program, the speed ref produced follows the filler drive analog output nearly the same as it's doing in real time.

The 'cans per minute' is translated into filler drive hertz on the HMI for the operator to understand. Basically 11375=185 CPM with a discharge conveyor speed of 64 hertz.

So bottom line the SCP type instruction seems to be my simple solution to seems overly complicated. I don't have weeks on this part of the code because it's merely the tip of the iceberg on this install.

thanks again

Why not just use the filler speed as the speed reference for the outgoing conveyors you will have to scale it but you will have to scale it any way you do it
One thing that may help is keep in mind that your discharge conveyor needs to run slightly faster than the filler to avoid jam ups
There are many ways to do the control system you want here but without having a lot more information I don’t see how anybody can give you more detailed help

GaryS said:

Why not just use the filler speed as the speed reference for the outgoing conveyors you will have to scale it but you will have to scale it any way you do it
One thing that may help is keep in mind that your discharge conveyor needs to run slightly faster than the filler to avoid jam ups
There are many ways to do the control system you want here but without having a lot more information I don’t see how anybody can give you more detailed help

Click to expand...

Thanks--that is basically what I'm doing. Taking the analog out from the filler and using it in a scp AOI with the scaled min and max being the conveyor speed reference. the variable range is based upon the ones currently functioning now. It seems to work well enough in a test instruction.

toddp65 said:

it's too complicated and in Italian.

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Let me fill you in on a little secret about speaking Italian:

http://blog.kappalanguageschool.com/wp-content/uploads/2017/07/3c6e9042ba611da13be39daed1980570.jpg

that helped tremendously--do you have a cheat for German as well?

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