Nice, The system you got in your exc is most common in barges and big exc doing underwater digging in harbours here in Norway.
The system moust used is Prolec PCX 3D.
I bet a Norwegian guy from GL Instruments, Jan Floberg, may have mounted the system you got in your machine?
Theese guy's and Prolec has invented the system together.
I have seen a demonstration in a huge exc mounted on a barge doing underwater digging for the new opera in Oslo.
You could se the bucket and the bottom, and the masses removed by each bucket. Calculates the amount constantly.
Realy impressing system, that i hear is cheap.(well, cheaper than the others)
But you are totaly independent of a computer...dont see much without one:bash