MC_MoveRelative

MC_MoveRelative 1:

The function block MC_MoveRelative starts a relative positioning procedure based on the current set position and monitors the axis movement over the whole travel path. The "Done" output is set once the target position has been reached. Otherwise, the output "CommandAborted" or, in case of an error, the output "Error" is set.

Motion commands can be applied to coupled slave axes, if this option was explicitly activated in the axis parameters. A motion command such as MC_MoveRelative then automatically leads to decoupling of the axis, after which the command is executed. In this case the only available BufferMode is "Aborting".

Inputs

VAR_INPUT
    Execute      : BOOL;
    Distance     : LREAL;
    Velocity     : LREAL;
    Acceleration : LREAL;
    Deceleration : LREAL;
    Jerk         : LREAL;
    BufferMode   : MC_BufferMode;
    Options      : ST_MoveOptions;
END_VAR

Name	Type	Description
Execute	BOOL	The command is executed with a rising edge.
Distance	LREAL	Relative distance to be used for positioning.
Velocity	LREAL	Maximum travel velocity (>0).
Acceleration	LREAL	Acceleration (≥0) If the value is 0, the standard acceleration from the axis configuration in the System Manager is used.
Deceleration	LREAL	Deceleration (≥0) If the value is 0, the standard deceleration from the axis configuration in the System Manager is used.
Jerk	LREAL	Jerk (≥0) At a value of 0, the standard jerk from the axis configuration in the System Manager is applied.
BufferMode	MC_BufferMode	Is evaluated if the axis is already executing another command. MC_MoveRelative becomes active after the current command or aborts it. Transition conditions from the current to the next command are also determined by the BufferMode. If the command is applied to a coupled slave axis, the only available BufferMode is "Aborting". A second function block is always required to use the BufferMode. It is not possible to trigger a move function block with new parameters while it is active.
Options	ST_MoveOptions	Data structure containing additional, rarely used parameters. The input can normally remain open.

Inputs/outputs

VAR_IN_OUT
    Axis : AXIS_REF;
END_VAR

Name	Type	Description
Axis	AXIS_REF	Axis data structure that unambiguously addresses an axis in the system. Among other parameters it contains the current axis status, including position, velocity or error state.

Outputs

VAR_OUTPUT
    Done           : BOOL;
    Busy           : BOOL;
    Active         : BOOL;
    CommandAborted : BOOL;
    Error          : BOOL;
    ErrorID        : UDINT;
END_VAR

Name	Type	Description
Done	BOOL	TRUE when the target position has been reached.
Busy	BOOL	TRUE as soon as the command is started with "Execute" and as long as the movement command is processed. If "Busy" is FALSE, the function block is ready for a new order. At the same time, one of the outputs "Done", "CommandAborted" or "Error" is set.
Active	BOOL	Indicates that the command is executed. If the command was buffered, it becomes active once a running command is completed.
CommandAborted	BOOL	TRUE if the command could not be executed completely. The axis was stopped or the current command was replaced by another Move command.
Error	BOOL	TRUE, if an error occurs.
ErrorID	UDINT	If the error output is set, this parameter supplies the error number.

	"Target Position Monitoring" is activated (standard case): when the logical positioning end is reached (the NC setpoint generation is finished and the HasJob bit is FALSE) AND afterwards the InPositionArea bit has become TRUE, then the Done output is set to TRUE. "Position Range Monitoring" is activated ("Target Position Monitoring" is not active): when the logical positioning end is reached (the NC setpoint generation is finished and the HasJob bit is FALSE) AND afterwards the InPositionArea bit has become TRUE, then the Done output is set to TRUE. Neither "Target Position Monitoring" nor "Position Range Monitoring" is activated: the Done output is set immediately when the logical positioning end is reached (the NC setpoint generation is ended and the HasJob bit is FALSE).

Requirements

Development environment	Target system type	PLC libraries to include
TwinCAT v3.0.0	PC or CX (x86 or x64)	Tc2_MC2