MC_MoveRelative

MC_MoveRelative 1:

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_MoveAbsolute then automatically leads to decoupling of the axis, after which the command is executed. In this case the only available buffer mode 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

Execute	The command is executed with a rising edge at Execute input.
Distance	Relative distance to be used for positioning.
Velocity	Maximum travel velocity (>0).
Acceleration	Acceleration (≥0). If the value is 0, the standard acceleration from the axis configuration in the System Manager is used.
Deceleration	Deceleration (≥0). If the value is 0, the standard deceleration from the axis configuration in the System Manager is used.
Jerk	Jerk (≥0). If the value is 0, the standard jerk from the axis configuration in the System Manager is used.
BufferMode	The BufferMode is analyzed, if the axis is already executing another command. The running command can be aborted, or the new command becomes active after the running command. The transition condition from the current to the next command is also defined by the BufferMode. If the command is applied to a coupled slave axis, only the buffer mode Aborting is possible. To use the BufferMode, a second function block is always necessary. It is not possible to trigger a move function block with new parameters while it is active.
Options	The data structure Options includes additional, rarely required parameters. The input can normally remain open.

General rules for MC function blocks

Outputs


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

Done	The Done output becomes TRUE once the target position was reached.
Busy	The Busy output becomes TRUE when the command is started with Execute and remains TRUE as long as the movement command is processed. If Busy becomes FALSE again, the function block is ready for a new order. At the same time one of the outputs, Done, CommandAborted or Error, is set.
Active	Active indicates that the command is executed. If the command was buffered, it becomes active once a running command is completed.
CommandAborted	Becomes TRUE, if the command could not be fully executed. The axis may have been stopped, or the running command may have been followed by a further Move command.
Error	Becomes TRUE if an error occurs.
ErrorID	If the error output is set, this parameter supplies the error number.

General rules for MC function blocks

Inputs/outputs


VAR_IN_OUT
    Axis    : AXIS_REF;
END_VAR

Axis

Axis data structure

The axis data structure of type AXIS_REF addresses an axis uniquely within the system. Among other parameters it contains the current axis status, including position, velocity or error status.