Detect value change in data block even if value is same as before

Hi,

I was wondering if it's possible to detect a changed/updated value in a data block even if the value remains the same as before.

The reason I ask is because we have a SCADA system providing a setpoint for a temperature every x minutes. The value of the setpoint can remain unchanged for hours even days.

However we still want the PLC to be able to detect wheather it's setpoint is updated every x minutes or not.

Any good solutions?

Thanks!