How mosaik communicates with a simulator¶
This section provides a general overview which API calls exists and when mosaik calls them. The following sections will go into more detail.
When the connection between a simulator and mosaik is established, mosaik will
init(), optionally passing some global parameters to the
simulator. The simulators returns some meta data describing itself.
Following this, mosaik may call
create() multiple times in order to
instantiate one of the models that the simulator implements. The return value
contains information describing the entities created.
The end of create phase and the beginning of the step (or simulation) phase
is marked by a call to
setup_done(). At this point, all entities are
created and all relations between them are established.
When the simulation has been started, mosaik repeatedly calls
allows the simulator to step forward in time. It returns the time at which it
wants to perform its next step.
Finally, mosaik sends a
stop() message to every simulator to request its
The following figure depicts the sequence of these messages:
step() have been called, there may be an
arbitrary amount of
get_data() calls where mosaik requests the current
values of some entities’ attributes:
These methods are usually sufficient to connect simple simulators to mosaik. However, control strategies, visualizations or database adapters may need to actively query mosaik for additional data.
Thus, while a simulator is executing a simulation step, it may make
asynchronous requests to mosaik. It can collect information about the
simulated topology (
get_related_entities()), request a new step for
set_event()), get the current simulation progress
get_progress()), query other entities for data (
and set data for other entities (