Check/Notification on any change of a field value

Dear all,

as I am quite new to InfluxDB I need some help with a specific problem. I have a field containing a csv string that gets updated at some point in time. Now what I want to do is to create a notification on any of these changes. I started creating a check but cannot find out what should be the threshold here, i think there is none, as I want to get notified (HTTP POST containing the value (csv) and the timestamp of the statechange) on ANY change of the value in that field.

Maybe you can help me to find a solution for this.

Thanks and BR,