  In this second article of the series we study holomorphic families of generic
rational matrix functions parameterized by the pole and zero loci. In
particular, the isoprincipal deformations of generic rational matrix functions
are proved to be isosemiresidual. The corresponding rational solutions of the
Schlesinger system are constructed and the explicit expression for the related
tau function is given. The main tool is the theory of joint system
representations for rational matrix functions with prescribed pole and zero
structures.
