MQTTClient (FB)¶

FUNCTION_BLOCK MQTTClient EXTENDS CBML.LCon

Function block to connect with a MQTT broker

InOut:

Scope	Name	Type	Initial	Comment	Inherited from
Input	`xEnable`	`BOOL`		`TRUE`: Activates the defined operation `FALSE`: Aborts/resets the defined operation	LCon
Output	`xDone`	`BOOL`		`TRUE`: Ready condition reached	LCon
	`xBusy`	`BOOL`		`TRUE`: Operation is running	LCon
	`xError`	`BOOL`		`TRUE`: Error condition reached	LCon
Input	`uiPort`	`UINT`		Port of MQTT Broker Server
	`xUseTLS`	`BOOL`		TRUE: Crypted Connection, FALSE: Uncrypted Connection
	`uiKeepAlive`	`UINT`	5	Keep Alive Time in Seconds (optional)
	`pbWillMessage`	POINTER TO BYTE	0	Pointer to the ‘Last Will’ message (optional)
	`uiWillMessageSize`	`UINT`	0	Size of ‘Last Will’ message (optional)
	`xWillRetain`	`BOOL`		TRUE: Saves the ‘Last Will’ message on server. If Client subscribes later, then it receives the last stack message from server.
	`eWillQoS`	MQTT_QOS		QoS Level of ‘Last Will’ message
	`xCleanSession`	`BOOL`		TRUE: Creates a new session, FALSE: Uses already existing session if available
	`wsUsername`	`WSTRING(255)`	“”	User Name (optional)
	`wsPassword`	`WSTRING(1024)`	“”	User Password (optional)
	`wsWillTopic`	`WSTRING(1024)`	“”	Will Topic (optional)
	`sClientId`	`STRING(255)`	‘’	Client ID, if empty then new ID is generated, allowed are only these characters 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ (optional)
	`tPingInterval`	`TIME`	TIME#2s0ms	Interval time in seconds how often should be pinged, if Time<=0 then no pings
	`hCert`	`RTS_IEC_HANDLE`	RTS_INVALID_HANDLE	Handle to the client certificate (optional)
	`itfTLSContext`	`NBS.ITLSContext`	0	Encapsulates all the data neccecray to handle encrypted tcp connections Static initialization, as shown in the following code snippet. VAR commonName : STRING := 'MyRrasPi'; ciCertInfo : NBS.CERT_INFO := (psInfo:=ADR(commonName), udiSize:=LEN(commonName)); myTLSContext : NBS.TLSContext := ( ePurpose:=NBS.PURPOSE.CLIENT_SIDE, sUseCaseName:='NBSTest', sTLSVersion:='1.3', ciCertInfo:=ciCertInfo, udiVerificationMode:=2 ); END_VAR
	`itfAsyncProperty`	`NBS.IAsyncProperty`	0	Runs the connect process in a own background task. Use this property if the connection setup takes longer than one task cycle (e.g. TLS connections)
	`udiTimeOut`	`UDINT`	0	Defines the time (µs) after which the connection setup aborts with xError.
	`eCommunicationMode`	COMMUNICATION_MODE	COMMUNICATION_MODE.TCP	Communication mode: TCP or WEB_SOCKET, default: TCP COMMUNICATION_MODE.TCP: Configure the connection via the inputs: sHostname, uiPort and itfTLSContext COMMUNICATION_MODE.WEB_SOCKET: Configure the connection via the inputs: sWebSocketUrl and itfTLSContext Additional WebSocket options can be set via the method SetWebSocketOptions.
	`sWebSocketUrl`	REFERENCE TO STRING(1024)		The uri of the websocket server. e.g ‘ws://localhost:8080’ ws-URI = “ws:” “//” host [ “:” port ] path [ “?” query ] wss-URI = “wss:” “//” host [ “:” port ] path [ “?” query ] The input is only relevant for eCommunicationMode = COMMUNICATION_MODE.WEB_SOCKET.
	`eMQTTVersion`	MQTT_VERSION	MQTT_VERSION.V3_1_1	MQTT protocol version, default: 3.1.1
	`mQTTConnectProperties`	REFERENCE TO MQTTConnectProperties		Connection properties for MQTT V5
	`mQTTWillProperties`	REFERENCE TO MQTTWillProperties		Will properties for MQTT V5
Inout Const	`sHostname`	`STRING(80)`		Host name of Broker MQTT Server (is IPAddress)
Output	`eMQTTError`	MQTT_ERROR		MQTT Error Type
	`xConnectedToBroker`	`BOOL`	FALSE	FALSE when there is no Connection to MQTT Broker Server, otherwise TRUE
	`eReaonCode`	MQTT_REASON_CODE		Reason code of the last operation (MQTT V5 only)
	`mQTTConnackProperties`	MQTTConnackProperties		Connection response properties (MQTT V5 only)

Methods:

SendAuthPacket

SetInitialValue

SetWebSocketOptions

Structure: