Initialization implied by InitializationModelSensor doesn't fit

[tobolar]

The enumeration TFS.Sensors.Internal.Types.InitializationModelSensor has two items steadyState and state. This implies that, during initialization of concerned models, either a) the state derivatives are set zero or b) the states can be given by user.

But IMO the implementation within the "initial equation" part of concerned models seems to be a bit different. Or it at least depends additionally on the boolean parameter filter_output.

See e.g. model TFS.Sensors.DifferenceSensor_Tp and others.