MC_Stop

 Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Aborts the active move, removes the next move from the queue, performs a controlled stop, and switches the axis to Stopping state.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	0, 1	N/A	No default	On the rising edge The transition of a digital signal from low to high. AKA: positive edge., request to stop the axis. It can be held high to prevent any other moves from being queued.
Axis	AXIS_REF	1, 256	N/A	No default	Name of a declared instance of the AXIS_REF library function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances.. See Axis Name and Number. See AXIS_REF Structure.
Deceleration	LREAL	No range	User unit/sec2	No default	Trapezoidal: Deceleration rate. S-curve: Unused. See S-curve and Trapezoidal Acceleration / Deceleration.
Jerk In physics, jerk is the rate of change of acceleration. More precisely, the derivative of acceleration with respect to time.	LREAL	No range	User unit/sec3	No default	Trapezoidal: 0 (zero). S-curve: Constant jerk. See S-curve and Trapezoidal Acceleration / Deceleration.

Outputs

Output	Data Type	Range	Unit	Description
Done	BOOL			Indicates both: The axis has reached zero velocity For a group of axes this means: In ACS the velocities of the different axes. In MCS and PCS it provides the velocity of the TCP. The Execute input is low.
Busy	BOOL			High from the time both: The Execute input goes high until the axis reaches zero velocity. The Execute input is low.
Active	BOOL			High from the time both: The MC_Stop move becomes the active move until the axis reaches zero velocity. The Execute input is low.
Error	BOOL			Indicates an invalid input was specified.
ErrorID	INT			Indicates the error if the Error output is set to TRUE. See PLCopen Function Block ErrorIDs.

Remarks

• 
  
• This function block starts a motion-related action and stores data for calculations and error checking.
  See Call Function Blocks Multiple Times in the Same Cycle if using a dual-core controller.

• See Function Blocks - General Rules about how inputs and outputs work.
• An MC_Stop cannot be aborted.
  • This means that, while in Stopping state, no function block can command any motion on the axis.
  • The axis remains in Stopping state until it reaches zero velocity and the Execute input is low.
• The application program The act of performing a sequence of instructions or commands. can hold the axis in Stopping state even after it reaches zero velocity by leaving the Execute input high.
• It aborts any ongoing function block execution.
• When the Done output is set, the state transfers to StandStill.
• While the axis is in Stopping state, no other FB can perform any motion on the same axis.

Figure 1: MC_Stop

Time Diagram

This example shows the behavior of the combination of a MC_Stop FB with a MC_MoveVelocity.

• A rotating axis is ramped The gradual acceleration and deceleration of a stepping motor. This is essential if performance beyond the start/stop range is required. The slope of the ramp is a function of screw pitch, load, drive voltage and design, and motor. down with FB2 MC_Stop
• The axis rejects motion commands as long as MC_Stop parameter “Execute” = TRUE

FB1 MC_MoveVelocity reports an error indicating the busy MC_Stop command.

Figure 2: Time Diagrams: First and Second FBs

Figure 3: Time Diagram

FBD Language Example

Not available.

FFLD Language Example

IL Language Example

Not available.

ST Language Example

            (* MC_Stop S
            T example *)

Inst_MC_Stop( StopRequest , Axis1, 100.0, 100.0 ); //Inst_MC_Stop is an instance of MC_Stop function block


StopComplete := Inst_MC_Stop.Done;     //store the Done output into a user defined variable

StopActive := Inst_MC_Stop.Active;     //store the Active output into a user defined variable

StopError := Inst_MC_Stop.Error;       //store the Error output into a user defined variable