  We investigate transport through a normal-superconductor (NS) junction made
from a quantum spin Hall (QSH) system with helical edge states and a
two-dimensional (2D) chiral topological superconductor (TSC) having a chiral
Majorana edge mode. We employ a two-dimensional extended four-band model for
HgTe-based quantum wells in a magnetic (Zeeman) field and subject to s-wave
superconductivity. We show using the Bogoliubov-de Gennes scattering formalism
that this structure provides a striking transport signal of a 2D TSC. As a
function of the sample width (or Fermi energy) the conductance resonances go
through a sequence of $2e^2/h$ (non-trivial phase) and $4e^2/h$ plateaux
(trivial phase) which fall within the region of a non-zero Chern number (2D
limit) as the sample width becomes large. These signatures are a manifestation
of the topological nature of the QSH effect and the TSC.
