PaSD bus health model

An implementation of a health model for a PaSD bus.

class PasdBusHealthModel(*args, **kwargs)

A health model for a PaSD bus.

At present this uses the base health model; this is a placeholder for a future, better implementation.

Even when updated, this health model should only ever represent the health of the PaSD bus itself. The health of individual PaSD devices (FNDH and smartboxes) will be represented by upstream Tango devices.