UA_ConnectGetStatus

This function block checks the connection status of an existing connection to another OPC UA Server. The connection is referenced via the respective connection handle. The status is then returned as E_UAConnectionStatus. The connection status is determined based on the internal session info or the OPC UA heartbeat, no additional communication (read or similar) is performed.

The service level of the OPC UA Server can be read out via the additional input parameter GetServiceLevel. For this purpose, a read command is sent to the server in the background to determine this information.

Inputs

VAR_INPUT
    Execute            : BOOL;
    ConnectionHdl      : DWORD;
    GetServiceLevel    : BOOL;     
    Timeout            : TIME := DEFAULT_ADS_TIMEOUT; 
END_VAR

Name	Type	Description
Execute	BOOL	The command is triggered by a rising edge at this input.
ConnectionHdl	DWORD	Connection handle of an existing communication link.
GetServiceLevel	BOOL	Reads out the ServiceLevel of the OPC UA Server.
Timeout	TIME	Time until the function is aborted. DEFAULT_ADS_TIMEOUT is a global constant, set to 5 seconds. The value must be set to match the ST_UASessionConnectInfo.tConnectionTimeout. The rule of thumb is: ADS Timeout > 2 * ConnectionTimeout.

Outputs

VAR_OUTPUT
    Done             : BOOL;
    Busy             : BOOL;
    Error            : BOOL;
    ErrorID          : DWORD;
    ConnectionStatus : E_UAConnectionStatus;
    ServerState      : E_UAServerState;
    ServiceLevel     : BYTE; 
END_VAR

Name	Type	Description
Done	BOOL	Switches to TRUE if the function block was executed successfully.
Busy	BOOL	TRUE until the function block has executed a command, at the most for the duration of the "Timeout" at the input. The inputs accept no new command as long as Busy = TRUE. It is not the connection time that is monitored but the reception time.
Error	BOOL	Switches to TRUE if an error occurs while executing a command. The command-specific error code is included in ErrorID.
ErrorID	DWORD	Contains the command-specific error code of the most recently executed command.
ConnectionStatus	E_UAConnectionStatus	Connection status (see E_UAConnectionStatus).
ServerState	E_UAServerState	Server state (see E_UAServerState).
ServerState	BYTE	ServiceLevel of the OPC UA Server.

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT 3.1	Win32, Win64, CE-X86, CE-Arm®	Tc3_PLCopen_OpcUa

PLC library	Required version
Tc3_PLCopen_OpcUa	>= 3.2.11.0