MC_Halt

The MC_Halt FB leads to stopping of motion. The motion stop is always jerk limited with the constant set input ‘Jerk’ for the braking rate. It aborts every ongoing command by other motion FBs. Contrary to the FB MC_Stop the FB MC_Halt may be aborted by commanding another motion FB. In this case, the output ‘CommandAborted’ is set.

The MC_Halt FB sets the ‘Done’ output as soon as the axis has stopped.

Block diagram

Parameter of the FB

VAR_IN_OUT
	Axis	AXIS_REF	Axis reference
VAR_INPUT
	Execute	BOOL	Start the action at rising edge.
	Deceleration	LREAL	Value of the deceleration (always positive). Range [1.0, 2147483647.0] Default unit [1mm/s² or 1°/s²]
	Jerk	LREAL	Value of the Jerk (always positive). Range [1.0, 2147483647.0] Default unit [1m/s³ or 1000°/s³]
VAR_OUTPUT
	Done	BOOL	Zero velocity reached and execute is not True.
	CommandAborted	BOOL	Command is aborted by another command.
	Error	BOOL	Indicates if an error has occurred.
	ErrorID	WORD	Error identification.

Behavior of the FB

Within the FB, the ‘Deceleration’ and ‘Jerk’ input variables are monitored only for their value ranges. If they are exceeded, an error number referring to the variable is output at the ‘ErrorID’ output and ‘Error’ is set to TRUE. Moreover, the ‘Deceleration’ value is limited within the motion controller. If a ‘Deceleration’ value of more than getriebe[0].dynamik.a_max is commanded, the motion is nevertheless run, but the values are limited to the defined values and a warning is issued.
Values that correspond to a minimum ramp time of T_A (cycle time of the IPO, e.g. 2 ms) and a maximum ramp time of 100s make sense as the ‘Jerk’. The limit transition to non-jerk-limited speed realization lies at the minimum ramp time of T_A. In the case of a value of 0, the maximum ramp time from the axis MDS is used to determine the ‘Jerk’.