By default, System Coupling's Log file reports Root Mean Square (RMS) convergence for data transfers for both the source and target side of the transfer. Convergence of the coupling step is evaluated at the end of each coupling iteration. Coupling step convergence requires that:
the target side RMS values have reached the convergence criteria that you specified in the input to the System Coupling setup, and
that the minimum number of coupling iterations that you specified are met.
If the coupling step is not yet converged, then a new coupling iteration is started. If the coupling step has converged, then a new coupling step is started if the coupling duration has not yet been reached.