MC_ReadParameter_BkPlcMc (from V3.0)

This function block reads the non-boolean parameters of an axis. The function block MC_ReadBoolParameter_BkPlcMc is available for boolean parameters.

Inputs

VAR_INPUT
    Enable:             BOOL;
    ParameterNumber:    INT;
END_VAR

Name	Type	Description
Enable	BOOL	A reading process is initiated by a rising edge at this input.
ParameterNumber	INT	This code number specifies the parameter that is to be read. Only named constants from E_TcMCParameter should be used.

Inputs/outputs

VAR_IN_OUT
    Axis:       AXIS_REF_BkPlcMc;
END_VAR

Name	Type	Description
Axis	AXIS_REF_BkPlcMc	Here, the address of a variable of type AXIS_REF_BkPlcMc should be transferred.

Outputs

VAR_OUTPUT
    Busy:       BOOL;
    Valid:      BOOL;
    Error:      BOOL;
    ErrorID:    UDINT;
    Value:      LREAL;
END_VAR

Name	Type	Description
Busy	BOOL	Indicates that a command is being processed.
Valid	BOOL	Successful execution of the reading process is indicated here.
Error	BOOL	The occurrence of an error is indicated here.
ErrorID	UDINT	An encoded indication of the cause of the error is provided here.
Value	LREAL	The value of the parameter is made available here.

Behavior of the function block

On a rising edge at Enable the function block checks the transferred axis interface. A number of problems can be detected and reported during this process:

If an unsupported value is given to ParameterNumber the system responds with Error and ErrorID:=dwTcHydErrCdNotSupport.

The desired parameter value is made available at Value, and Done is asserted if these checks can be carried out without problems.

A falling edge at Enable clears all the pending output signals.

	This function block requires no time for executing its tasks. The output Busy will never assume the value TRUE and only exists for compatibility reasons.