Arc Motion Center and Angle

The arc motion command can be used to move an XBot in an arc path, the arc is defined by the arc center location, the rotation angle, and the rotation direction (clockwise or counterclockwise).

Fieldbus Interface

PMC_ArcMotionCenter

Inputs

Name	Data Type	Description
Execute	BOOL	Execution of the function block begins on a rising edge of this input.
cmdLB	UINT	Any 2 byte Command Label, user defined.
XbotID	USINT	ID of the XBot. Real XBot IDs [1,78]. Virtual XBot IDs [100,127]. Macro IDs [128,191]
Mode	USINT	0: Absolute position of Arc Center; 1: Relative positioning of arc center to XBot position at the start of command execution
Dir	USINT	0: Negative RZ direction (Clockwise); 1: Positive RZ direction (Counterclockwise)
EndVel	REAL	Ending Tangential Speed (m/s)
MaxVel	REAL	Maximum Tangential Speed (m/s)
MaxAcc	REAL	Maximum Acceleration (m/s2)
CenterX	REAL	Center X Coordinates (m)
CenterY	REAL	Center Y Coordinates (m)
Angle	REAL	Angle (rad) – must be greater than 0
PM_Controller	PMControllerType	Data structure that specifies which PMC to connect to. There should be only 1 instance of this variable for each connected PMC.

Outputs

Name	Data Type	Description
Ack	BOOL	Command has been accepted by the PMC when Ack = TRUE.
Done	BOOL	Execution successful. Function block is finished. (Note: Done will not become TRUE if Execute is already FALSE)
Busy	BOOL	Function block is active and must continue to be called.
Aborted	BOOL	Command aborted by another command.
Error	BOOL	If there is an error in processing the command, then Error = TRUE, otherwise, FALSE.
ErrorID	UINT	0x0: All OK. Otherwise, please see PMC Reply Codes.
TravelTime	REAL	Traveling time (s)

Ethernet Interface

MotionRtn ArcMotionMetersDegrees(ushort cmdLabel, int xbotID, ARCMODE arcMode, ARCTYPE arcType, ARCDIRECTION arcDir, POSITIONMODE positionMode, double XMeters, double YMeters, double finalSpeedMetersPs, double maxSpeedMetersPs, double maxAccelerationMetersPs2, double radiusMeters, double angleRadians)

Parameters

Name	Type	Description
cmdLabel	ushort	Any 2 byte Command Label, user defined.
xbotID	int	ID of the XBot. Real XBot IDs [1,78]. Virtual XBot IDs [100,127]. Macro IDs [128,191]
arcMode	enum	TARGETRADIUS (0) = Target + Radius mode, CENTERANGLE (1) = Center + Angle mode
arcType	enum	MINORARC (0) = minor arc, MAJORARC (1) = major arc
arcDir	enum	CLOCKWISE (0) = clockwise, COUNTERCLOCKWISE (1) = counterclockwise
positionMode	enum	ABSOLUTE (0) = absolute positioning, RELATIVE(1) = relative positioning
XMeters	double	Target X (target + radius mode) or Center X (center = angle mode), meters
YMeters	double	Target Y (target + radius mode) or Center Y (center = angle mode), meters
finalSpeedMetersPs	double	Final tangential speed (m/s)
maxSpeedMetersPs	double	Max tangential speed (m/s)
maxAccelerationMetersPs2	double	Max acceleration (m/s2)
radiusMeters	double	For target + radius mode only: radius of arc, meters
angleRadians	double	For center + angle mode only: arc angle, radians

Returns

Name	Type	Description
MotionRtn.PmcRtn	PMCRTN enum	ALLOK (0): Command Accepted. Otherwise, please see Ethernet Reply Codes.
MotionRtn.TravelTimeSecs	float	Time required to complete this command, in seconds

Conditions

Operating Conditions
Preconditions	XBot is in the Idle state, Obstacle Detected state, Motion state, Stopped state, Hold Position state, or Waiting state.
Postconditions	If the XBot is ready to immediately begin executing the command, then the XBot will enter the Motion state. Otherwise, the XBot state remains unchanged, but the command will be added to the XBot's motion buffer.

Description

The arc motion command can be used to move an XBot in an arc path, the arc is defined by the arc center location, the rotation angle, and the rotation direction (clockwise or counterclockwise).

The target or center position can be specified either in absolute coordinates or relative coordinates. Relative coordinates are relative to the reference position of the XBot when the command begins execution.
Only the X- and Y-positions (also called the long axis) are controlled by this command. The Z-, Rx-, Ry-, and Rz-positions are maintained during this motion command.
The maximum speed and ending speed must be specified. Similar to linear motion, the input maximum speed will be automatically constrained if it is below or above the system limits and the ending speed will be limited if the travel distance is too short
The ending speed and maximum speed are also limited by both the tangential and the normal acceleration for the arc. The speeds may be automatically adjusted to a lower value if required so that the accelerations do not exceed their limits.