MC_MoveCircularAbsolute¶
MC_MoveCircularAbsolute
This Function Block commands an interpolated circular movement on an axes group from the actual position of the TCP. The end point as well as the auxiliary point (meaning depending on applied mode, see below) are defined absolutely in the specified coordinate system.
Note
This Function Block applies to the MCS or PCS System, depending which is activated and also follows the dynamic transformation when activated
This Function Block is only supported for PLC-based central Motion Control with Coordinated Motion structures.
CircMode = BORDER
The user defines the end point and a border point (= input ‘AuxPoint’) on the sector of the circle, which shall be cruised by the machine.
Advantages of this mode:
- The border point usually can be reached by the machine, i.e. it can be teached.
Inconvenience of this mode:
- Restriction to angles<2π in one single command.
CircMode = CENTER
The user defines the end point and the center point (= input ‘AuxPoint’) of the circle. When using this mode, the input ‘PathChoice’ defines, if the short or the long sector has to be cruised by the machine.
Inconveniencies of this mode:
- Restriction to angles < 2π and ≠π in one single command,
- Overdetermination of circle equation,
- The center point usually cannot be teached in due to collisions with obstacles.
CircMode = RADIUS
The user defines the end point and the perpendicular vector of the circle plane according to the rule of right thumb (see figure below). The length of the vector corresponds to the radius of the circle. The spearhead point of the vector is the input signal ‘AuxPoint’ in absolute coordinates, i.e. referring to the origine of the coordinate system specified in ‘CoordSystem’. If the diameter is larger than the distance between starting and end point, two different circles have to be considered. When using this mode, the input ‘PathChoice’ defines, if the circle with the short sector or the circle with the long sector to reach the end point has to be cruised by the machine. With positive radius value the shortest possible circle is determined, and with negative radius value the largest possible circle.
Inconvenience of this mode:
- Restriction to angles < 2π in one single command,
- Overdetermination of circle equation.
Example:
AuxPoint = (50,0,0) ®Circle in plane parallel to y-z plane with radius 50 and rotation around axis parallel to x-axis according to the rule of right thumb (CoordSystem = MCS).
MC_MoveCircularAbsolute - Sequenced example
Sequenced example of 2 MC_MoveCircularAbsolute Function Blocks:
Example MC_MoveCircularAbsolute
Timing diagram of example above. The dots on the red line are based on the same timing difference and representing thevelocity:
Example MC_MoveCircularAbsolute