  We study profiles and gauge invariant observables of classical solutions
corresponding to a constant magnetic field on a torus in open string field
theory. We numerically find that the profile is not discontinuous on the torus,
although the solution describes topologically nontrivial configurations in the
context of low energy effective theory. From the gauge invariant observables,
we show that the solution provide correct couplings of closed strings to a
D-brane with constant magnetic field.
