MC_WriteParameter

This function block corresponds to the function block described in PLCopen for writing parameters.

Three steps are carried out when writing a parameter with this function block:

Writing the parameter value into the work list
Activating the work list (parameters take effect in the ISG-MCP)
Storing the work list back to the original list

This means that a parameter value that is written with this FB also takes effect immediately and is permanently stored.

This FB is not suitable for consistently writing several parameter values. In this case, you must use the MCV_ChgParamValue, MCV_ActivateParamChg and MCV_SaveParamChg function blocks.

CAUTION
The current implementation only supports writing of the axis lists (achsmdsX.lis). Default lists (default_achs_mds.lis) are not supported.

CAUTION
During the write operation, the axis must be at standstill and motion commands must not have been or must not be started for the axis. The axis must not be moved again until the parameter has been written and the new value is active in the controller (output ‘Done’ = TRUE).

CAUTION
For modification of a parameter, this function block requires an original list that can be read in by the controller without warnings and error messages.

	The parameter set 0 and the list type ‘ACHS_MDS’ are used by default.

Block diagram

Parameters of the FB

VAR_IN_OUT
	Axis	AXIS_REF	Axis reference.
VAR_INPUT
	Execute	BOOL	Write the value of the parameter at rising edge.
	ParameterNumber	STRING	Number/Identification of the parameter to be written, e.g. ‘kenngr.swe_pos’.
	ParameterType	STRING	Kind of parameter to be written. Current: ACHS_MDS
	Value	STRING	New value of the parameter.
VAR_OUTPUT
	Done	BOOL	Parameter successfully written.
	Busy	BOOL	The FB with the ‘Busy’ = TRUE has control on the axis.
	Error	BOOL	Indicates if an error has occurred.
	ErrorID	WORD	Error identification.
	InternalErrorID	UDINT	Internal error identification of the ISG-MCP.

Behavior of the FB

A frequent cause of ISG-MCP errors are absent write privileges or a write-protected work list or original list because, in these cases, a work list is not created or an original list cannot be replaced.