Display the Timestamp for the Last Time a Tag Changed Value/State

I'm trying to make an axiom application showing various current "live" data of many tags sampled every second.  Some tags are related to automated discrete volume sampling from the instrument and reported back to it from the companion diagnostic instrument.  The primary instrument reports this tag every second as an OPC tag - but i want to report the timestamp for when the most recent "Step change" occurred in the past.

Is this possible for the "Value Box" using aggregation trickery?  Or do we need more sophistication to make that happen?