"Target sequence activation" function

Objective

This function is used to synchronize a slave axis and master axis to a preset position.

This synchronization is performed using the "SetMasterTriggerPosition" and "FollowOn" functions.

Operation

The slave axis is stopped while the master axis is in motion.

The user activates the function using OPCODE 574 "LinkOnTarget". Once it receives the request, the module calculates the threshold position of the master.

When the position of the master axis crosses the threshold calculated by the system, the slave axis starts its motion according to the acceleration ramp set up.

The slave axis takes into account:

"Target position of the slave/master axes" torque,
the current master position,
the current master speed,
the current slave position,
the Master/Slave ratio,
the acceleration configured for the slave.

This function applies where the master remains at a constant speed between the function’s time of launch and sequence activation "bit AXIS_IS_LINKED = 1". Also, the master cannot be a remote axis.

"LinkOnTarget" function

Both rotation directions (positive and negative) are authorized,
the master axis can be real or imaginary,
the master axis can be configured in modulo,
the slave axis can be configured in modulo.

The command is given by a WRITE_CMD sent to the slave group channel:

Object	Type	Symbol	Explanation	Comment
%MWr.m.c.19	Word	ERROR_CMD		Command rejected *
%MDr.m.c.20	Double word	RETURN_CMD_1
%MFr.m.c.22	Floating point	RETURN_CMD_2		Activation position of the master (equivalent to the "GetMasterTriggerPosition" function)
%MFr.m.c.24	Floating point	RETURN_CMD_3		Time remaining before sequence activation of the slave (in seconds)
%MWr.m.c.26	Word	ACTION_CMD	574	LinkOnTarget
%MDr.m.c.27	Double word	PARAM_CMD_1	SlaveNumber	SERCOS address of the slave to link
%MDr.m.c.29	Double word	PARAM_CMD_2	0	not used
%MFr.m.c.31	Floating point	PARAM_CMD_3	MasterPosition	Target position of master axis
%MFr.m.c.33	Floating point	PARAM_CMD_4	SlavePosition	Target position of slave axis

* Command refused:

slave already linked: 69
slave in motion: 70
master stopped: 72
master in wrong rotation direction: 71
master not configured: 37
master is remote axis: 37
slave not configured in this group: 37
slave not configured: 7003
group not configured: 7002

Notes:

The speed of the master must remain constant between the time of the sequence activation request and the sequence activation ("bit AXIS_IS_LINKED = 1").