MC_TrackConveyorBelt

TF5410 TwinCAT 3 Motion Collision Avoidance	TF5420 TwinCAT 3 Motion Pick-and-Place
	MC Group with Pick-and-Place	MC Group Coordinated Motion
	(up to and including v3.2)

The function block Mc_TrackConveyorBelt enables a reference system that is in motion. It synchronizes the AxesGroup with the ConveyorBelt in terms of velocity.

Synchronization with a position requires a motion command.

The function block thus helps to synchronize with an object that moves in a straight line through space. Example: products moving on a conveyor belt or other transport system.

The origin of the conveyor belt is parameterized with a coordinate system (CoordTransform). X is the conveying direction. The detected object position (InitialObjectPos) and the corresponding touch probe position (MasterRefPos) are entered in the function block.

Synchronization dynamics can be entered in the function block.

Movements executed after Active = TRUE are synchronized with the conveyor belt.

Execution of MC_TrackConveyorBelt with another instance causes direct synchronization with a second conveyor belt.

When changing the reference system, a conveyor belt can be decoupled.

	Use case for changing the reference system The `MC` group can be decoupled by using `MC_TrackConveyorBelt` and changing the reference system. The reference system can be changed with `MC_SetCoordinateTransform`.

News and optimizations regarding MC_TrackConveryorBelt with TF5400 V3.2.27 for MC Group Coordinated Motion

New: Optionally, the override also affects the synchronization phase for the MC_TrackConveyorBelt. The setting is made in the parameter "Tracking Override Behavior" in the MC Group Coordinated Motion.
Optimizations to the MC_TrackConveyorBelt that prevent SAF cycle misalignment between conveyor (master) and slave axis.
Optimizations of the error reaction for the MC_TrackConveyorBelt. In the event of a runtime error of the conveyor belt (master), an active MC_MovePath is not aborted and an error reaction is to be triggered via the PLC.

Inputs

VAR_INPUT
    Execute               : BOOL;
    CoordTransform        : MC_COORD_REF;
    InitialObjectPos      : POINTER TO MC_LREAL;
    InitialObjectPosCount : UDINT;
    MasterRefPos          : MC_LREAL;
    Velocity              : MC_LREAL := MC_DEFAULT;
    Acceleration          : MC_LREAL := MC_DEFAULT;
    Deceleration          : MC_LREAL := MC_DEFAULT;
    Jerk                  : MC_LREAL := MC_DEFAULT;
END_VAR

Name	Type	Description
Execute	BOOL	The command is triggered by a rising edge at this input.
CoordTransform	MC_COORD_REF	Reference to a coordinate system (see MC_COORD_REF).
InitialObjectPos	POINTER TO MC_LREAL	Pointer to array `[1..InitialObjectPosCount]`.
InitialObjectPosCount	UDINT	Dimension of the `InitialObjectPos` vector.
MasterRefPos	MC_LREAL	Touch probe position.
Velocity	MC_LREAL	Velocity for synchronization. The velocity must exceed the conveyor belt velocity. The velocity is not limited by the maximum axis velocity.
Acceleration	MC_LREAL	Used in the Conveyor Tracking object. The acceleration for synchronization. The acceleration is not limited by the maximum axis acceleration. If no value is entered, then the default acceleration of the Conveyor Tracking object is used.
Deceleration	MC_LREAL	Used in the Conveyor Tracking object. The deceleration for synchronization. The deceleration is not limited by the maximum axis deceleration. If no value is entered, then the default deceleration of the Conveyor Tracking object is used.
Jerk	MC_LREAL	The jerk for synchronization. If no value is entered, then the default jerk of the Conveyor Tracking object is used. The maximum jerk is not limited.

Inputs/outputs

VAR_IN_OUT
    AxesGroup             : AXES_GROUP_REF;
    ConveyorBelt          : AXIS_REF;
END_VAR

Name	Type	Description
AxesGroup	AXES_GROUP_REF	Reference to a group of axes (see Cyclic Group Interface).
ConveyorBelt	AXIS_REF	Reference to an axis. Reference to the conveyor axis.

Outputs

VAR_OUTPUT
    InSync                : BOOL;
    Busy                  : BOOL;
    Active                : BOOL;
    CommandAborted        : BOOL;
    Error                 : BOOL;
    ErrorId               : UDINT;
END_VAR

Name	Type	Description
InSync	BOOL	The output `InSync` becomes `TRUE` for the first time when the slave is synchronized with the velocity. If the slave dynamics is too low to follow the master movement, the output `InSync` could be reset to `FALSE`, after which the slave axis starts synchronizing again. Notice Velocity synchronization: Active and InSync - the function block MC_TrackConveyorBelt synchronizes the AxesGroup with the velocity of the ConveyorBelt axis. The function block uses the given parameters for Acceleration, Deceleration and Jerk. When this synchronization movement begins, Active is set to TRUE. When the velocity of the ConveyorBelt is reached, InSync is set to TRUE. The synchronization status is continuously monitored and indicated with InSync. Notice Conveyor movement, default tracking behavior and InSync - once the output signal InSync has been set, there are two options to maintain synchronization. mcTrackingBehaviorDynLimited - this behavior is the default (MC_Default) tracking behavior. The AxesGroup maintains velocity synchronization with the ConveyorBelt using the given parameters for Acceleration, Deceleration and Jerk. – mcTrackingBehaviorStayInSync - the AxesGroup maintains the velocity synchronization with the ConveyorBelt with unlimited parameters for Acceleration, Deceleration and Jerk. Notice Position synchronization: MasterRefPos and InitialObjectPos - the function blocks MC_TrackConveyorBelt and MC_MovePath should be used together for flexible synchronization with a moving target position. After MC_TrackConveyorBelt.Active is set to TRUE, InitialObjectPos and the distance to MasterRefPos are appended to the next call to MC_MovePath. MC_TrackConveyorBelt.InSync = TRUE and MC_MovePath.Done = TRUE indicate that the synchronized position has been reached.
Busy	BOOL	This output becomes `TRUE` when the command is started with `Execute` and remains so as long as the function block executes the command. If `BUSY` becomes `FALSE` again, the function block is ready for a new command. At the same time, one of the outputs `CommandAborted` or `Error` is set.
Active	BOOL	If `Active` is `TRUE`, the function block controls the group.
CommandAborted	BOOL	This output becomes `TRUE` if the command was interrupted by another command.
Error	BOOL	This output becomes `TRUE` if an error has occurred during command execution.
ErrorId	UDINT	Contains the command-specific error code of the last executed command. Details of the error code can be found in the ADS error documentation or in the NC error documentation (error codes 0x4nnn and 0x8nnn).

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT V3.1.4022.25 TF5400 Advanced Motion Pack V3.1.6.03	PC or CX (x64)	Tc3_McCoordinatedMotion, Tc2_MC2