  We study the numerical propagation of waves through future null infinity in a
conformally compactified spacetime. We introduce an artificial cosmological
constant, which allows us some control over the causal structure near null
infinity. We exploit this freedom to ensure that all light cones are tilted
outward in a region near null infinity, which allows us to impose
excision-style boundary conditions in our finite difference code. In this
preliminary study we consider electromagnetic waves propagating in a static,
conformally compactified spacetime.
