MC_Stop

MC_Stop 1:

The function block MC_Stop is used to stop an axis with a defined deceleration ramp and to lock the axis against other motion commands. The function block is therefore suitable for stops in special situations, in which further axis movements are to be prevented.

At the same time the axis is blocked for other motion commands. The axis can only be restarted once the Execute signal has been set to FALSE after the axis has stopped. A few cycles are required to release the axis after a falling edge of Execute. During this phase the "Busy" output remains TRUE, and the function block has to be called until "Busy" becomes FALSE.

The locking of the axis is canceled with an MC_Reset.

Alternatively, the axis can be stopped with MC_Halt without locking. MC_Halt is preferable for normal movement sequences.

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_Stop then automatically leads to decoupling of the axis, after which the command is executed.

Inputs

VAR_INPUT
    Execute      : BOOL; 
    Deceleration : LREAL; 
    Jerk         : LREAL;
    Options      : ST_MoveOptions; 
END_VAR

Name	Type	Description
Execute	BOOL	The command is executed with a rising edge. The axis is locked during the stop. The axis can only be restarted once the Execute signal has been set to FALSE after the axis has stopped.
Deceleration	LREAL	Deceleration If the value is ≤ 0, the deceleration parameterized with the last Move command is used. For safety reasons MC_Stop and MC_Halt cannot be executed with weaker dynamics than the currently active motion command. The parameterization is adjusted automatically, if necessary.
Jerk	LREAL	Jerk If the value is ≤ 0, the jerk parameterized with the last Move command is used. For safety reasons MC_Stop and MC_Halt cannot be executed with weaker dynamics than the currently active motion command. The parameterization is adjusted automatically, if necessary.
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 if the axis has been stopped and is stationary.
Busy	BOOL	TRUE as soon as the command is started with Execute and as long as the command is processed. If "Busy" is FALSE, the function block is ready for a new order. "Busy" remains TRUE as long as the axis is locked. The axis is only unlocked and "Busy" becomes FALSE when Execute is set to FALSE.
Active	BOOL	Indicates that the function block controls the axis. Remains TRUE as long as the axis is locked. The axis is only unlocked and "Active" becomes FALSE when Execute is set to FALSE.
CommandAborted	BOOL	TRUE if the command could not be executed completely.
Error	BOOL	TRUE, if an error occurs.
ErrorID	UDINT	If the error output is set, this parameter supplies the error number.

Requirements

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