Hi
Are there any way of zeroing values with a broken OPC connection ?
Im playing around with a PLC with OPC-UA and Ignition Perspective.
I see the values in the UDTs and OPC-UA but when i disconnect the PLC the "old" values stays on screen.
I want it to preferely show Null or somthing similar to show that the OPC-UA connection has failed and that the values are not to be trusted.
The docs are rather vague on Perspective's overlay options - apart from the symbols. (Vision overlays are well documented.)
I've put in a request to docs@inductiveautomation.com for some additional material in that page.
Do you not get an error overlay when the tag quality goes bad? I would avoid displaying '0'. The general idea is that displaying the last known value but with an error overlay might be more useful than displaying a zero value without an overlay which might, for example, indicate that a line is stopped or the temperature is at 0°, etc.
The only thing i see changes when i unplug the PLC are OPC quality goes from Good to Uncertain_LastKnownValue.
Even the ErrorStatus seems unchanged. Only the OPC Quality.
I was looking only in the UDTs, i see the values/tags on the Page get a black dot now.
I thought it would be a red border and red dot. (I think that's how it shows up in Designer anyway.) You can always create an expression binding on the displayed value and use the Expression Language's isGood(), isBad() or isBadOrError() functions to alter the display.
I see it depends.
When i break a existing opc connection i get a black dot "UncertainLastValue"
If it is a unconnected unit that has never been read i gets a red Dot/Border "Bad Connection" or other "Bad" error
This behavior is deeply buried in Ignition's tag system and happens with all OPC connection types.
