MCA_GearInDirect (FB)

FUNCTION_BLOCK MCA_GearInDirect

This function block commands a gear ratio between the position of the slave and master axes from the synchronization point onwards.

The function block behaves as follows:

• Synchronization starts right away, no matter if the master moves or is in standstill.

• The synchronization is limited by the given velocity and acceleration, achieved as fast as possible, so it can happen that:

• The 2 axes are synchronized earlier than the two given positions

• The 2 axes are synchronized later than the two given positions

• Following formula is used:

  • SlavePosition = (masterPosition - MasterSyncPosition) * RatioNumerator/RatioDenumerator + SlaveSyncPosition

• In a modulo-axis, it is possible to reach the synchronization point in different directions.

The input parameter SyncDirection with its possible values: POSITIVE, NEGATIVE or SHORTEST can be used to set this direction. Inside the SyncWindow, automatically the direction SHORTEST will be used. It is important to set a SyncWindow > 0 for a modulo axis. Otherwise, slightest deviations could result in moving a complete modulo distance.

• Inside SyncWindow, the slave axis will move SHORTEST to reach the SlaveSyncPosition

• Outside SyncWIndow, it will move the given SyncDirection, which can be POSITIVE or NEGATIVE

• If a direction POSITIVE or NEGATIVE is used in a linear axis, the slave will wait until the master reaches a position which allows the slave to move the required direction.

InOut:

Scope	Name	Type	Comment
Input	Execute	BOOL	Starts the function block at rising edge
	RatioNumerator	DINT	Gear ratio numerator, new value is updated only with rising edge of Execute input
	RatioDenominator	DINT	Gear ratio denominator, new value is updated only with rising edge of Execute input
	MasterValueSource	MC_Source	Decides to use the actual position or reference position of master axis. mcSetValue - Synchronization on master set value. mcActualValue - Synchronization on master actual value
	MasterSyncPosition	LREAL	The position of the master where the slave is insync with the master
	SlaveSyncPosition	LREAL	Slave Position at which the axes are running in sync
	SyncDirection	MC_Direction	Moving direction for the slave to start the movement. Applicable: POSITIVE or NEGATIVE, use SHORTEST for any other value
	SyncWindow	LREAL	[u], Used to determine the moving direction, combined with SyncDirection When the slave is outside the SyncWindow, it will move the direction which is given in SyncDirection When the slave is inside the SyncWindow, it will move SHORTEST to meet the SlaveSyncPosition
	Velocity	LREAL	[u/s], Velocity which limits the synchronization movement. The slave has to be able to move faster than the master axis, otherwise it is possible the SlaveSyncPosition is never reached when the master starts to move. Range: >0
	Acceleration	LREAL	[u/s°°2], Acceleration which limits the synchronization movement. Range: >0,If value = 0, Acceleration will be equal to parameter paraMaxVelocityAppl.If value > 0 and <= 1,Acceleration will be limited to 1.
	BufferMode	MC_BufferMode	Not supported, default mcABORTING used
Output	StartSync	BOOL	Synchronization was started
	InSync	BOOL	Commanded gearing completed
	Busy	BOOL	The function block is not finished
	Active	BOOL	Indicates that the function block has control on the axis
	CommandAborted	BOOL	Command is aborted by another command from other PLCopen function block
	Error	BOOL	Signals that error has occurred within function block
	ErrorID	ERROR_ID	Error identification. For error details refer to Enumeration ERROR_ID
Inout	Master	Axis_Ref	Reference to master axis
	Slave	Axis_Ref	Reference to slave axis