  We prove pointwise convergence for the scattering data of a Dirac system of
differential equations. Equivalently, we prove an analog of Carleson's theorem
on almost everywhere convergence of Fourier series for a version of the
non-linear Fourier transform. Our proofs are based on the study of resonances
of Dirac systems using families of meromorphic inner functions, generated by a
Ricatti equation corresponding to the system.
