The mqttSend block sends to the MQTT test broker
test.mosquitto.org at
topic "mdd-example". The mqttReceive block subscribes
to the same broker at the same topic "mdd-example". Consequently,
the mqttReceive block receives what the
mqttSend block sends.
Note: There is no causality between the
mqttSend block and the mqttReceive block.
Therefore the execution order of the blocks is not determined.
Additionally, the mqttReceive block starts an own
receiving thread, so that the time the data was received is not
equal to the time the external function within the
mqttReceive block was called. This indeterminism may
also show up in the plots.