pylab_ml.common.mqtt_client.mqtt_init

class mqtt_init(*args, **kwargs)[source]

Bases: object

Initialise the mqtt connection and provide functions for the communication.

__init__(typ='control', logger=None)[source]

Initialise the class mqtt_init.

Parameters:

  • typ (str) – ‘instrument’ for instruments ‘control’ for guis or extern controlling (default)

  • logger (mylogger or None) – Logger instance for logging messages. If None, no logging is performed.

Methods

__init__([typ, logger])

Initialise the class mqtt_init.

clearpublish(attr)

Remove retained publish message from broker

close()

Close the MQTT client connection and clean up resources.

init([broker, port, message_client, ...])

Normally call from plugin semi-control, you have not to call this function, if you use semi-control.

mqtt_add(instrument[, hostname])

Add first callback to get mqtt-commands from control, and append instrument to instruments-list.

mqtt_disconnect([instrument, hostname])

Remove instrument from the instruments-list, if instruments-list is empty than remove callback.

mqtt_receive(topic, msg)

publish(attr, value[, qos, retain])

Publish a message to the MQTT broker.
clearpublish(attr)[source]

Remove retained publish message from broker

Parameters:

attr (str) – The topic attribute for which the retained message should be removed.

Return type:

None

close()[source]

Close the MQTT client connection and clean up resources.

init(broker='127.0.0.1', port=1883, message_client=None, username='', userpasswd='', qos=0, retain=False)[source]

Normally call from plugin semi-control, you have not to call this function, if you use semi-control.

Parameters:

  • broker (str) – The address of the MQTT broker (default: “127.0.0.1”)

  • port (int) – The port of the MQTT broker (default: 1883)

  • message_client (str or None) – None if client the instrument, like e.q. smu, digital-multimeter or thermostreamer. eg. ‘DT1604092’ if control and you want connect from an extern computer to DT1604092 (but is not checked until now!!)

  • username (str) – The username for MQTT authentication (default: “”)

  • userpasswd (str) – The password for MQTT authentication (default: “”)

  • qos (int) – The Quality of Service level for MQTT messages (default: 0)

  • retain (bool) – Whether to retain MQTT messages (default: False)

Returns:

True if the MQTT client was successfully initialized and connected to the broker, False otherwise.

Return type:

bool

mqtt_add(instrument, hostname=None)[source]

Add first callback to get mqtt-commands from control, and append instrument to instruments-list.

Parameters:

  • instrument (object) – The instrument to be added to the MQTT client.

  • hostname (str or None) – The hostname for the MQTT topic. If None, the client’s hostname will be used (default: None).

Return type:

None

mqtt_disconnect(instrument=None, hostname=None)[source]

Remove instrument from the instruments-list, if instruments-list is empty than remove callback.

Parameters:

  • instrument (object or None) – The instrument to be removed from the MQTT client. If None, no instrument will be removed (default: None).

  • hostname (str or None) – The hostname for the MQTT topic. If None, the client’s hostname will be used (default: None).

Return type:

None

publish(attr, value, qos=None, retain=None)[source]

Publish a message to the MQTT broker.

Parameters:

  • attr (str) – The topic attribute to publish.

  • value (any) – The value to publish. This will be converted to a JSON string before publishing.

  • qos (int or None) – The Quality of Service level for the MQTT message. If None, the default QoS level of the client will be used (default: None).

  • retain (bool or None) – Whether to retain the MQTT message. If None, the default retain flag of the client will be used (default: None).

Return type:

None