Data Interconnect specifies the paths between the archive's measurement instruments — which files each reads, which it writes, and where a value computed by one becomes an input to another — so that a change in any instrument's output has a traceable consequence downstream.
The motivation is that a measurement stack whose couplings are undocumented will drift silently: an instrument's definition changes, its consumers keep running, and nothing reports that the downstream numbers now mean something else. The specification is falsifiable in a direct way — a coupling that exists in code but not in the document, or vice versa, is a defect.