MCV_ReadParamValue

Read parameter value

This function block reads the parameter values from the original list or work list of a selected parameter set. If the parameter searched for is in the original list that still exists, it is returned as the "old parameter". If a work list exists and contains the parameter value, it is returned as the "new parameter".

Notice

The parameter value effective in the controller may differ from the two parameter values read in if the parameter value was corrected in the controller due to a warning when interpreting the original or work list.

After activation without a warning, the parameter value in the work list is active in the controller. Otherwise, the value of the original list is taken.

Block diagram

FB parameters

VAR_IN_OUT
Variable name	Data type	Description
Axis	AXIS_REF	Axis reference
VAR_INPUT
Variable name	Data type	Description
Execute	BOOL	The changed parameters are saved on the rising edge.
NCListTypeIn	STRING	Identifier for parameter or list type e.g. "ACHS_MDS"
NCParamSetIDIn	UINT	Number of the parameter set from which the parameter value is to be read.
NCParamIdentIn	STRING	Identifier of the parameter whose value is to be read, e.g.“kenngr.swe_pos“
VAR_OUTPUT
Variable name	Data type	Description
Valid	BOOL	Is TRUE when the change parameters were saved successfully.
Busy	BOOL	Is TRUE if the FB is still active.
NCListTypeOut	STRING	Identifier for parameter or list type e.g. "ACHS_MDS"
NCParamSetIDOut	UINT	Number of the parameter set which was read from the parameter value.
NCParamIdentOut	STRING	Identifier for parameter or list type e.g. “kenngr.swe_pos”
NCOldParamValueRead	BOOL	Is TRUE if the parameter identifier was in the original list.
NCOldParamValueOut	STRING	Parameter value from the original list.
NCNewParamValueRead	BOOL	Is TRUE if the parameter identifier was in the work list.
NCNewParamValueOut	STRING	Parameter value from the work list.
NCWarning	BOOL	Is TRUE if a warning occurred in the ISG-MCP.
NCError	BOOL	Is TRUE if an error occurred in the MCE when a parameter value is read.
NCErrorCode	UDINT	Error code of the error or warning occurring in the ISG-MCP.
Error	BOOL	Is TRUE if the FB is in error state. Saving the changed parameters was not successful.
ErrorID	WORD	Error code

¹) Availability is dependent on the MCE used.

Behaviour of the FB:

The FB is in an error state if "Error" = TRUE. The parameter value could not be read correctly. An error occurred either in the function block itself or in the ISG-MCP. The "NCError" output parameter indicates whether an error occurred in the ISG-MCP.
The ISG-MCP returns an error if the parameter value is not in any of the lists.
If the value of a parameter is determined from the active parameter set, the code of the active parameter set is first determined by an instance of the MCV_ReqParamSetID. This code is applied to the “NCParamSetIDIn” input of the MCV_ReadParamValue The parameter value from the active parameter set is then applied to the “NCOldParamValueOut” output and is valid when the “NCOldParamValueRead” output = TRUE. If a work list exists at the same time, the value from it is indicated at the “NCNewParamValueOut” output.