Description

Function Description

The function block UA_MonitoredItemOperList updates the values of a list of variables. It also updates the corresponding information in the associated lists (for example, ValuesChanged, TimeStamps and NodeQualityIDs) of the control program. This function block can be used to control when the variable will be refreshed in the application.

Representation in FBD

Parameter Description

Input parameters:
Name	Type	Comment
EXECUTE	BOOL	FB performs its task on rising edge on this input.
SUBSCRIPTIONHDL	DWORD	Subscription handle.
MONITOREDHDLCOUNT	UINT	Number of valid elements in the array to refresh.
MONITOREDHDLS	ANY_ARRAY_DWORD	Array of Monitored Node Handles

Output parameters:
Name	Type	Comment
DONE	BOOL	FB has successfully completed its task
BUSY	BOOL	The FB is not finished and new output values are to be expected.
ERROR	BOOL	Signals that an error has occurred within the FB. Set to true is either ErrorID or any of the NodeErrorIDs indicates an error.
ERRORID	DWORD	Error code
NODEERRORIDS	ANY_ARRAY_DWORD	Array of DWORD. Contains an error code for each valid element of the MonitoredItemHdls array.
PUBLISHED	BOOL	Indicates, that variables have been published since the last call. At least one element of the array of ValuesChanged will be true.

This function block is used when the underlying system will not automatically update the variable values After the successful execution it is expected, that the variable values and the corresponding information in the associated lists (for example, ValuesChanged, TimeStamps and NodeQualityIDs) have been updated.

Runtime Error

Refer to the Appendix for a list of OPC UA detected error codes.