Handling Prompts across multiple HMIs

I'd like to see what creative ways others have come up with for handling prompts on multi-HMI systems.

We recently added a second HMI for a customer and need to improvise how we are handling PLC-driven prompts. Currently, on the PanelView Plus, we have the PLC change the screen number for the prompt to display it, forcing the operator to make a decision. On the new Red Lion we just installed, we want to do something similar, but my concern is if the operator acknowledges the prompt on one, it will still exist on the other. Ideally, the second prompt would disappear upon interaction with the other, but that's not really possible. I'm leaning toward buttons with visibility.

Each indicator needs a bit in the PLC to determine if it is visible. Then, when something is acknowledged on one, it will become hidden on the rest. I'm not sure what kind of object would handle that, though. Probably something on your background screen that checks for that "visible" bit and displays the screen/object if so.

I would think all you would need to do is have a "Macro" running so when a change is made it would make changes to whatever you have it programmed to do.

sparkie said:

Each indicator needs a bit in the PLC to determine if it is visible. Then, when something is acknowledged on one, it will become hidden on the rest. I'm not sure what kind of object would handle that, though. Probably something on your background screen that checks for that "visible" bit and displays the screen/object if so.

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Thanks. I have no problem with this aspect of it. I am asking more in terms of actual prompts. Thanks though!

damica1 said:

I would think all you would need to do is have a "Macro" running so when a change is made it would make changes to whatever you have it programmed to do.

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When event occurs, the prompt would appear on both screens. When either one is acknowledged, the prompt should disappear on the other screen as user input is no longer required.

I suspect that using two different HMI's will complicate the programming issue because they won't necessarily react the same. It might be less expensive in the long run to use another PV Plus and clone the existing PV program.

mendonsy said:

I suspect that using two different HMI's will complicate the programming issue because they won't necessarily react the same. It might be less expensive in the long run to use another PV Plus and clone the existing PV program.

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Not quite that simple, unfortunately. Still need a way to cancel the popup on one when the other is acknowledged. I don't see a way to do that in FT View ME.

Is there a thinclient/vnc type mode where you can duplicate the display?

Otherwise I think a rework of the system with macros to clear is easiest idea

In the PLC what you could do is right before you jump to the other screen, capture the present screen number of each HMI. When one HMI acknowledges the screen have the PLC change the screen back to what it was on the second HMI.

phuz said:

I'd like to see what creative ways others have come up with for handling prompts on multi-HMI systems.

We recently added a second HMI for a customer and need to improvise how we are handling PLC-driven prompts. Currently, on the PanelView Plus, we have the PLC change the screen number for the prompt to display it, forcing the operator to make a decision. On the new Red Lion we just installed, we want to do something similar, but my concern is if the operator acknowledges the prompt on one, it will still exist on the other. Ideally, the second prompt would disappear upon interaction with the other, but that's not really possible. I'm leaning toward buttons with visibility.

Click to expand...

You need to think carefully about this....

What is the purpose of the second HMI ? Who will use it ?

Do you want all prompts to be acknowledged independently, by each operator, so that it is guaranteed they have seen it ?

Should one operator be allowed to acknowledge a prompt without the other seeing it ?

Are there some prompts that you only want specific HMIs to display ? (i.e. different operators controlling different parts of the process....). perhaps the prompts should be split into different HMIs.

We are so used to seeing the "one machine, one HMI" scenario, that we tend to forget the practicalities, the security, the nuisance factors.

I suggest you answer the above questions without thinking how to program it, then, when you have a clear idea what it is you want, you can proceed to the programming...

I second daba. Separate hmi’s are a pain in the arse. Especially if manual controls are involved. Assign a different macro for both then do the rest in the plc. Flexibility and updates are much easier that way.

For PanelView, Wonderware and FTView I use code (or for PV the Terminal ActiveX control) to detect the terminals IP address and then use that to dynamically look a a different HMIx tag in the PLC (Typically ControlLogix). Where x is Area1, Area2 etc. Then you can control the popups individually.

You could use the PLC to call "previousScreen" in the HMI if you have that option available? Not sure if AB has that option though