Unable to write into the Aoi tags

Hi I am unable to change value of the PLC AOI tag “C15_Totalizer_Scale.LoadCellLength” through the Numeric Entry Field Button on perspectives. I set the binding property to bidirectional.

The external access property of the AOI parameter is read /write.
The controller is L36ERM version 32.11.

Is there an issue writing value to the AOI tags directly in ignition? How can i solve it?

If you navigate to that tag in the Quick Client or the Tag Browser and write a value to it do you get an error or does the value just not change?

I tried changing the value directly in the tag browser. It acts like refreshing for a sec. and revert back to the original value. So to answer your question. There is no error on the tag. and the value just not change

I suggest you take a closer look at your PLC logic then.

This scenario happens with relative frequency (write succeeds, value doesn’t change) and I can’t remember a time it was ever something besides a problem with the PLC logic overriding or resetting the value.



Which Ignition version you are using?


I am also facing the same issue with Ignition version 8.1.7, value entered from the numeric entry field is not updating in the PLC. I am using Kepserver, Micrologix 1400.

If I change the value by 0.1 or 0.2 then it is not updating in the PLC, If I changed it by 0.5 or more then it is updating in the PLC.

Hello all, Please help on this.

Have you defined a deadband on the tag?

1 Like


Yes, Deadband Mode is Absolute and Deadband is 0.1.

I can able to change value by 0.1 after setting the Deadband mode OFF.

Thank you very much!