Device programming

General Discussion
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I am putting this in the General forum because it is really vague and sort of nebulous and could technically apply to other software besides Ignition, but that is what I am using.

I am a software engineer by trade and was put in charge of Ignition for a new plant we’ve built. I am not looking for specific answers to questions, but instead I am looking for direction on where I can read and learn about how to answer these questions. Any and all guidance is appreciated and I hope you can bear with me through what might be a painful explanation…

I have a device in a plant that I need to program/schedule using Ignition.

I have a mixer, ran by a motor, and the motor is driven by an Allen Bradley Powerflex 755.

I need to run the mixer on a schedule:

  • If the mixer is set to ‘Auto’
  • Run Forward/Reverse depending on the schedule
  • Set a specific speed for the mixer

The scheduling is taken care of in Ignition, that was actually quite easy with a couple of emails to IA support. However, figuring out how to exactly control the motor/mixer has left me vexed.

I’ve read over the documentation and I am coming up short on everything.

I look in Ignition and I see a lot of tags for the motor/mixer. Tag examples:

  • ForwardPB
  • ForwardCMD
  • ReversePB
  • ReverseCMD
  • AutoMode
  • ManStart
  • ManStop
  • SpeedActual
  • SpeedActualPercent

My question is, how do I know what values to write to which tags? I mean, I can infer some of what I need to do based on tag names and some previously written software in Ignition. But if I want to run the mixer in forward how do I know that I am supposed to write ‘x, y, z’ to tags ‘a, b, c’.

Where would that be documented? I don’t see anything that even remotely resembles those tag names in any of the docs that I have access to. Is this something that I am just supposed to know as a controls/scada/etc person? Am I missing a a piece of the puzzle?

I have documentation on the Powerflex, the mixer/motor, and I have Ignition. Is there more documentation I should be looking at? Is there another piece of software I can use to look at the configuration of the tags and what the mean?

I hope this isn’t too incredibly convoluted and I know my lack of knowledge is showing but I am running out of resources.

Thanks everyone.

1 Like
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From your post, I couldn’t see if there is some PLC involved in controlling the motor/mixer.
You mentioned only Powerflex 755.
Normally there’s a PLC present where all logic for controlling the production process is programmed.
With SCADA software (Ignition here) you connect to the PLC over some kind of network, normally ethernet. That’s why all SCADA software has included (free or for a price) drivers for most common PLC’s on the market.
Then is the PLC programmers job to tell/give you all the tags addresses and explanation, what’s each tag for inside PLC
(Many people are both: PLC and SCADA programmers; so for them, it’s easy to tell them self… :slight_smile:).
It’s also PLC programmers job to learn how to establish the communication between PLC and VFD (over the network or digital/analog I/O’s).

It’s rare (I’ve never used it) to control some VFD without PLC and with SCADA…
Only VFD without PLC and without SCADA yes, but SCADA without PLC… no…

SCADA (Supervisory control and data acquisition; https://en.wikipedia.org/wiki/SCADA) is not meant to do PLC’s job.
SCADA’s job is collecting data and control the process (send control signals to the PLC which then controls the field devices).

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EDIT: This is a replay to a private message:

While I don’t know Allen Bradley Powerflex devices (or Allen Bradley in general; here in Europe are not very popular) it’s possible for field devices to act as simple ‘PLC’s’. I’ve done something like that with Siemens servo drive.
If you have the device configured in Ignition and it’s connected (who configured it?) then this means that inside the Ignition Designer you have access to Powerflex ‘tags’…
Now, what are this tags and what are the addresses of this tags… that’s something you must get from Powerflex documentation or people who set up the Powerflex device.
Usually, the ‘tags’ are parameters inside the device for various purposes. Each parameter has its own address in device memory space.
In order to configure this tags inside the SCADA/Ignition, you must know these addresses and its formats (boolean, integer, float,…) and the syntax for configuring this tags. While I can’t help you with that because I don’t know anything about Control Logix PLCs and Allen Bradley (I’m Siemens guy for almost 30 years :-)), maybe there is something inside the Ignition help https://docs.inductiveautomation.com/display/DOC79/UDT+Inheritance
to start with…

And I’m sure that here on the forum are people who know the Allen Bradley and Powerflex devices and how to connect/control them from Ignition. :+1:

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For clarification, zxcslo's second post is in reply to this msg from me (warning, my ignorance is appalling in this exchange :slight_smile: ):

Ahh, ok bear with me because my ignorance is really going to show here.... again.

I thought the Powerflex was considered the PLC in this case but I guess it is not? What nomenclature should I use for that in this layout? (I realize how painfully obvious this answer is and that I should know it.)

I dug through my Ignition configuration. I see we have a device listed in the system as our 'Main PLC and it is an 'Allen-Bradley Logix Driver'. If I could get documentation on that device, would it point me in the right direction?

So I suppose I need to find out more about my PLC and how it is programmed. zxcslo has given me some insight and better understanding but I am still trying to track down the needed information to get this mixer running in the right manner. If anyone else has any input or guidance, it is greatly appreciated. Thanks all.

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not rare at all with architecture class drives, the 75x drives can execute code independant of the drive and pids. its called drive logix.