Prevent "Uncertain, showing last value"

Hello together.
In my first topic i want to say hello.
My name is Tobias, i am responsible for machine data colletion in our company with igntion and SAP.
We have plants in USA, Brazil, Russia, China and so on… I am from germany / bavaria and say hello.

Now i have a litttle problem. We collect machine datas about ignition. But if the machine is switched off, we get always the last values. In designer it shows “Uncertain, showing last value”.
But we don’t need it. And i don’t find any solution to switch off that.

Thx Tobias

Welcome to the forum, Tobias. What would you like to get when a machine is off?

  1. Show last value, but don’t show uncertain overlay (check “Overlay Opt-Out” in binding)
  2. Don’t show it at all (use an expression on visible property to hide it based on tag quality)
  3. Show something else (use an expression to show something else based on tag quality)

Or have I misunderstood your question?


Tanks for answer. Sorry I think myy explaination was inexact. The main problem is, we use igntion also for data transport to other systems.
If the maschine is switch off, we get always the last values.

For example this picures. On is the state from ignition (designer)… And the other are the values in our subprogram.
The machine is not running.

Is there any settings in Ignition where i can say, if the device is disconneced, don’t show values…


No, but every tag read delivers both value and quality. Inspect the quality in your scripting/expressions and substitute whatever you want to show when the quality code indicates your machine is disconnected.

1 Like

More on tag quality:

“No”… ok, thanks.
Thats was it what i want to know. I asked because in other OPC programms you have the possibility.
I thought i can solve it without a script for each tag.

Thanks for the link.