alert triggered by fixed float rather than raw data

[LeoChen]

Dears,

    How should I do to trigger alert by fixed float on TWX?

    For example, tag A is float with 8 decimal point, and alert will be triggered when A > 2.10. Now A is equal to 2.10000099, and alert should not be triggered because A is 2.10 when fixed to 2 decimal points.

    could you help me to make this? Thanks very much.

[Rocko · Accepted solution]

You could try to set Data Change Type to Value and Data Change Threshold to 0.01 on the thing property. Not sure if that works.

Or you create a second property whose value is set by subscription to the original property and the value is always trunc(event.newValue)

[LeoChen]

Thank you for your reply.

But different alerts are running with this tag, other alerts will be changed with Data Change Threshold changing.

[Rocko]

Then go with the second option, or get the source that is updating the property to use the right precision.