Is there a better way?

John Morris · Mar 21, 2017

Good Morning all

L30ER, RSLogix 5000 Mini, 1769 IQ16 (8mS OFF/ON)

I have 6 actuators, using a IQ16 to read the 24v OFF/ON pulses of the encoder feedback. (It's within range of the cards capability)

According to other relevant sources the way to do this is with a periodic task.

Are there any other ways to achieve and compile the pulse feedback.

Any and all appreciated

Thank you for your time with this.

AustralIan · Mar 21, 2017

Is there a better way?

No

Are there any other ways to achieve and compile the pulse feedback.

Use a CTU in the continuous task. Ensure using other methods that your continuous task scan time never exceeds your required sampling interval.

John Morris · Mar 21, 2017

Many thanks to you Sir

GTUnit · Mar 21, 2017

We put encoder counters in the Periodic Task with a higher priority and execution time that guarantees no pulses are missed.

John Morris · Mar 22, 2017

Thank you Sir

I need to ask a rookie question thought. How do I get local tags into and out of the main routine.

Thank you

Jeev · Mar 22, 2017

John Morris said:
How do I get local tags into and out of the main routine.

Is there some restriction that requires you to use Local Tags? Use Controller Tags instead.

AustralIan · Mar 22, 2017

http://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm004_-en-p.pdf

Check out "Tag Scope" and "Program parameter scope" chapters of the above.

has a coupe of useful diagrams in there too.

Note that Program parameter scope is only available after a certain version.

Global scope tags are the more technician friendly version.

John Morris · Mar 22, 2017

Hmm,

No not really, but all the control is in the subroutine in the main.

My thought was just to read pulses from the actuator, count them, and import that back to the subroutine controlling the output to the actuator.

John Morris · Mar 22, 2017

OK

That's what I needed......................

Thank you for the pointer Ian.

AustralIan · Mar 22, 2017

You're welcome John

John Morris · Mar 22, 2017

My brain hurts

This is the scenario. I want the actuators to go to three defined positions. Retracted, somewhere in the middle, and somewhere towards the end. ( I'll clear that up closer to the end of the build) These only get set once during the process then retract after its complete.

If I create a periodic task, can I......receive pulses, process, and control output all from inside the periodic.

Next, I have six actuators, can all of them be assigned to one periodic or should I use one task for each actuator.

I'm gonna go eat some aspirin now...............

AustralIan · Mar 22, 2017

John Morris said:
My brain hurts

Try reducing stress in your life, and better regulating your coffee mg/hr

John Morris said:
If I create a periodic task, can I......receive pulses, process, and control output all from inside the periodic.

Yes. Think of it exactly like a continuous task, except it executes at a fixed rate.

John Morris said:
Next, I have six actuators, can all of them be assigned to one periodic or should I use one task for each actuator.

All in one.

John Morris said:
I'm gonna go eat some aspirin now...............

Noted.

John Morris · Mar 22, 2017

Reducing caffeine intake = some has to die

Headache is coming from trying to learn a new language, and think in 3D at a higher level.

That, and it has to go on line in six days.

You've helped quite a bit and I appreciate your time

Thank you

Is there a better way?

John Morris

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AustralIan

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John Morris

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GTUnit

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John Morris

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Jeev

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John Morris

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John Morris

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AustralIan

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John Morris

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John Morris

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