We present a software tool -- extended Dynamic Causal Modelling for Phase Coupling (eDCM PC) -- that is able to estimate effective connectivity between any kind of oscillating systems, e.g. distant brain regions, using the phase information obtained from experimental signals. With the help of a transformation function eDCM PC can measure observable independent coupling functions within and between different frequency bands. eDCM PC is written in the numerical computing language MATLAB as an extension to Dynamic Causal Modelling (DCM) for phase coupling (Penny et al. 2009). eDCM PC is available on GitLab under the GNU General Public License (Version 3 or later).