MC_MoveAbsolute (FB)

FUNCTION_BLOCK MC_MoveAbsolute

This function block commands a controlled motion to a specified absolute position.

• This action completes with velocity zero if no further action are pending.

• If there is only one mathematical solution to reach the commanded position (like in linear systems), the value of the input direction is ignored.

• For modulo axis, valid absolute position values are in the range of [0, [360, (360 is excluded), or corresponding range. The application, however, may shift the commanded position of MC_MoveAbsolute into the corresponding modulo range. For relative positions, modulo 360 is applicable.

• The Enum type “shortest_way” is focused to a trajectory which will go through the shortest route. The decision which direction to go is based on the current position where the command is issued.

Note

With every rising edge at “Execute”, modified input parameters will be used.

Example

The following figure shows two examples of the combination of two function blocks MC_MoveAbsolute.

1. The left part of timing diagram illustrates the case if the second function block is called after the first one. If first reaches the commanded position of 6000 (and the velocity is 0) then the output Done causes the second function block to move to the position 10000.

2. The right part of the timing diagram illustrates the case if the second move function block starts the execution while the first function block is still executing. In this case the first motion is interrupted and aborted by the test signal during the constant velocity of the first Function Block. The second function block moves directly to the position 10000 although the position of 6000 is not yet reached

Note

Input validation is done at the rising edge of Execute. If function block is in Active/Busy state, new value at input will not be validated. If value passed is invalid function block will continue execution with paraMaxVelocityAppl value i.e., (Max application velocity).

InOut:

Scope	Name	Type	Comment
Input	Execute	BOOL	Starts the function block at rising edge
	Position	LREAL	[u] Reference position. Range: Maximum range is 16#7FFFFFFF in increments, if configured in units, range will be limited to equivalent of 16#7FFFFFFF increments
	Velocity	LREAL	[u/s] Value of the maximum velocity (not necessarily reached). Range: >0. If value = 0, velocity will be equal to the parameter paraMaxVelocityAppl
	Acceleration	LREAL	[u/s°°2] Value of the acceleration (increasing energy of the motor). Range: >0. If value = 0, Acceleration will be equal to parameter paraMaxAccelerationAppl
	Deceleration	LREAL	[u/s°°2] Value of the deceleration (decreasing energy of the motor). Range: >0. If value = 0, Deceleration will be equal to parameter paraMaxDecelerationAppl
	Jerk	LREAL	[u/s°°3] Value of the Jerk. Range: >=0
	Direction	MC_Direction	Positive, shortest, negative, current, positive_stop, negative_stop, Current_Stop
	BufferMode	MC_BufferMode	Not supported, default mcABORTING used
Output	Done	BOOL	Shows the status of the function block. Done = TRUE if the execution is finished
	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	Axis	Axis_Ref	Reference to axis