defmod nwpm_mqtt_client MQTT2_CLIENT 192.168.178.38:61894
attr nwpm_mqtt_client clientId nwpm_mqtt_client
attr nwpm_mqtt_client mqttVersion 3.1.1
attr nwpm_mqtt_client subscriptions gateway/iothub/twin_reported_state extern/nwpm_mqtt_client/#
attr nwpm_mqtt_client username mqtt
attr nwpm_mqtt_client verbose 5

defmod nwpm_mqtt_device MQTT2_DEVICE
attr nwpm_mqtt_device IODev nwpm_mqtt_client
attr nwpm_mqtt_device getList modbus_get modbus_get_result gateway/modbus/get_value/$EVTPART1 {"name":"$EVTPART1","mqtt_msg_properties":{"response_topic":"extern/nwpm_mqtt_client/get_value_reply/$EVTPART1","correlation_data": 0}}
attr nwpm_mqtt_device readingList nwpm_mqtt_client:gateway/iothub/twin_reported_state:.* twin_reported_state\ nwpm_mqtt_client:gateway/iothub/twin_reported_state:.* { json2nameValue($EVENT) }\ nwpm_mqtt_client:extern/nwpm_mqtt_client/get_value_reply/.*:.* modbus_get_result
attr nwpm_mqtt_device setList modbus_set gateway/modbus/set_value/$EVTPART1 {"name":"$EVTPART1","value":["$EVTPART2"],"mqtt_msg_properties":{"response_topic":"","correlation_data": 0}}\ modbus_set_multiple gateway/modbus/set_value/$EVTPART1 {"name":"$EVTPART1","value":$EVTPART2,"mqtt_msg_properties":{"response_topic":"","correlation_data": 0}}

heatpumpMqtt.things file:

Bridge mqtt:broker:heatpump [ host="192.168.178.38", secure=false , port=61894, username="mqtt", password="80B56598 ",reconnectTime=30000, clientId="openhabClientHeatpump" ]{
  Thing topic values {
  Channels:
    Type number : outsideTemp "Outside temperature " [ stateTopic="gateway/iothub/twin_reported_state", transformationPattern="JSONPATH:$.telemetry.1301a" ]
    Type number : opMode_manual "Manual operation mode" [ stateTopic="gateway/iothub/twin_reported_state", transformationPattern="JSONPATH:$.telemetry.714i", commandTopic="gateway/modbus/set_value/714i", formatBeforePublish="{\"name\": \"714i\",\"value\":[\"%d\"],\"mqtt_msg_properties\": {\"correlation_data\": 0, \"response_topic\": \"extern/openhabClientHeatpump/response\"}}"]
    }
}

heatpumpMqtt.items file:
Number Heatpump_OT "Outside temperature [%.1f °C]" {channel="mqtt:topic:heatpump:values:outsideTemp"}
Number Heatpump_opMode "Manual operation mode %s" {channel="mqtt:topic: heatpump:values:opMode"}

on({id: "mqtt.0.gateway.iothub.twin_reported_state", change: "any"}, function (obj) { ParseTwinReportedState(obj); });
CreateOrSetState('mqtt.0.input.modbus_set_state', 'modbus_set_state', '', true);
on({id: "javascript.0.mqtt.0.input.modbus_set_state", change: "any"}, function (obj) { HandleModbusSetStateInput(obj); });
CreateOrSetState('mqtt.0.input.modbus_get_state', 'modbus_get_state', '', true);
on({id: "javascript.0.mqtt.0.input.modbus_get_state", change: "any"}, funktion (obj) { HandleModbusGetStateInput(obj); });

function ParseTwinReportedState(obj) {
  try {
    var rootJson = JSON.parse(obj.state.val);
    var jsonTable = [];
    Object.keys(rootJson).forEach(function(outerKey) {
      var innerJson = rootJson[outerKey];
      Object.keys(innerJson).forEach(function(innerKey) {
        CreateOrSetState('mqtt.0.parsed.twin_reported_state.' + outerKey + '.' + innerKey, innerKey, innerJson[innerKey]);
        jsonTable.push({Name: innerKey, Value: innerJson[innerKey]});
      });
    });
    CreateOrSetState('mqtt.0.parsed.twin_reported_state_table', 'twin_reported_state_table', JSON.stringify(jsonTable));
  } catch (e) {console.error("Error in ParseTwinReportedState(): " + e);}
}

function HandleModbusSetStateInput(obj) {
  try{
    var inputSplit = obj.state.val.split(" ");
    if(inputSplit.length < 2) return;
    var modbusIdx = inputSplit[0];
    var valArray = [];
    for(var i=1; i<inputSplit.length; i++){valArray.push(inputSplit[i]);}
    var modbusSetJSON = {
      name: modbusIdx,
      value: valArray,
      mqtt_msg_properties: {response_topic: "extern/iobroker/set_value_reply", correlation_data: 0}
    }
    sendTo('mqtt.0', 'sendMessage2Client', {topic: 'gateway/modbus/set_value/' + modbusIdx, message: JSON.stringify(modbusSetJSON)});
  }
  catch (e) {console.error("Error in ParseModbusSetState(): " + e);}
}

function HandleModbusGetStateInput(obj) {
  try{
    var modbusIdx = obj.state.val;
    if(modbusIdx.length < 1) return;
    var modbusGetJSON = {
      name: modbusIdx,
      mqtt_msg_properties: {response_topic: "extern/iobroker/get_value_reply", correlation_data: 0}
    }
    sendTo('mqtt.0', 'sendMessage2Client', {topic: 'gateway/modbus/get_value/' + modbusIdx, message: JSON.stringify(modbusGetJSON)});
  } catch (e) {console.error("Error in ParseModbusGetState(): " + e);}
}

function CreateOrSetState(objectId, objectName, objectValue, onlyCreate = false){
  if(!existsState(objectId)) createState(objectId, objectValue,{name: objectName, type: 'string', role: 'value'}, function () {});
  else if(!onlyCreate) setState(objectId, objectValue);
}