Communication protocol

The communication has to be initiated from the external control workstation which sends a command request and receives the robot state as response

Note

The communication protocol byte order, size and alignment uses the network byte order (which is always big-endian as defined in IETF RFC 1700)

The following subsections describe the communication protocol, allowing the development of APIs in other programming languages, e.g.

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Request (command)

Command code	Arguments	Description
0	-	Empty command. Useful for requesting only the status of the robot e.g.
101	-	Stop the robot motion
102	7-element numeric array (axis 1 to 7)	Control robot using axis/joint positions (in radians). Arguments with NaN values will maintain their current state
103	6-element numeric array (Cartesian position (3) and orientation (3))	Control robot using Cartesian pose (in millimeters and radians). Arguments with NaN values will maintain their current state
104	6-element numeric array (auxiliary position (3) and end position (3))	Perform a circular motion (in millimeters)
201	Numeric value in range [0, 1]	Define the axis-specific relative velocity (% of maximum velocity)
202	Numeric value in range [0, 1]	Define the axis-specific relative acceleration (% of maximum acceleration)
203	Numeric value in range [0, 1]	Define the axis-specific relative jerk (% of maximum jerk)
204	Numeric value in range [0, 1]	Define the absolute Cartesian velocity in millimeters per second
205	Numeric value in range [0, 1]	Define the absolute Cartesian acceleration in millimeters per second squared
206	Numeric value in range [0, 1]	Define the absolute Cartesian jerk in millimeters per second cubed
211	6-element numeric array (threshold (3) in range [0, Inf) and tolerance (3) in range [0, Inf))	Define the force condition, in Newtons, for each Cartesian axis. Arguments with NaN values will not be set (or will be reset if they had any value)
212	Non negative integer (axis index starting at zero) and 2-element numeric array (lower and upper limits (2))	Define the axis/joint torque condition (lower and upper limits), in Newton-meter, for the indicated axis. Axis with NaN values will not be set (or will be reset if they had any value)
221	7-element numeric array (translational stiffness (3) in range [0, 5000], rotational stiffness (3) in range [0, 300], null space stiffness (1) in range [0, Inf))	Define the stiffness (translational stiffness in Newtons per meter, rotational stiffness in Newton-meters per radians, and spring stiffness of the redundancy degree of freedom in Newton-meters per radians) for the Cartesian impedance control
222	7-element numeric array (translational damping (3) in range [0.1, 1], rotational damping (3) in range [0.1, 1], null space damping (1) in range [0.3, 1])	Define the damping (translational damping, rotational damping, and spring damping of the redundancy degree of freedom) for the Cartesian impedance control
223	6-element numeric array (translational (3) and rotational (3) additional control forces)	Define the additional control force (translational control force in Newtons and rotational control force in Newton-meter) for the Cartesian impedance control
224	6-element numeric array (maximum force (3) and torque (3)) and boolean value as a number (whether to enable a stop condition)	Define the limitation of the maximum force (translational in Newtons) / torque (rotational in Newton-meter) on the TCP
225	6-element numeric array (translational (3) in range [0, Inf) and rotational (3) in range [0, Inf))	Define the maximum Cartesian velocity (translational in millimeters per seconds and rotational in radians per seconds) at which motion is aborted if the limit is exceeded
226	6-element numeric array (translational (3) in range [0, Inf) and rotational (3) in range [0, Inf))	Define the maximum permissible Cartesian path deviation (translational in millimetersand rotational in radians) at which motion is aborted if the limit is exceeded
227	7-element numeric array (axis 1 to 7) in range [0, Inf)	Define the stiffness, in Newton-meter per radians, for joint impedance control
228	7-element numeric array (axis 1 to 7) in range [0, 1]	Define the damping for joint impedance control
229		Define the Cartesian overlaid force oscillation amplitude
230		Define the Cartesian overlaid force oscillation frequency
231		Define the Cartesian overlaid force oscillation phase
232		Define the Cartesian overlaid force oscillation bias
233		Define the Cartesian overlaid force oscillation foce limit
234		Define the Cartesian overlaid force oscillation position limit
235		Define the Cartesian overlaid force oscillation total time
236		Define the Cartesian overlaid force oscillation rise time
237		Define the Cartesian overlaid force oscillation hold time
238		Define the Cartesian overlaid force oscillation fall time
239		Define whether the Cartesian overlaid force oscillation is terminated or continued after the end of the motion
240	3-element numeric array (Cartesian DOF, force and stiffness)	Overlay a constant force, in one Cartesian direction
241	4-element numeric array (Cartesian DOF, frequency, amplitude and stiffness)	Overlay a simple force oscillation in one Cartesian direction
242	4-element numeric array (Cartesian plane, frequency, amplitude and stiffness)	Overlay a 2-dimensional oscillation in one plane (Lissajous curve)
243	5-element numeric array (Cartesian plane, frequency, amplitude and stiffness and total time)	Overlay a spiral-shaped force oscillation in one plane
301	Enumeration value (1). See Communication modes	Set the communication mode
302	Enumeration value (1). See Control interfaces	Set the control interface
303	Enumeration value (1). See Motion types	Set the motion type
304	Enumeration value (1). See Control modes	Set the control mode
305	Enumeration value (1). See Execution types	Set the execution type
400	Non negative integer (starting at zero) for attaching the tool. -1 for detaching the tool	Attach/detach tool

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Response (robot state)

Data	Description	Index	Length	Interpreted type
Command status	Whether the requested command was successfully executed or scheduled	0	1	Boolean
Joint positions	Axis - specific actual position in radians (axis 1 to 7)	1	7	Numeric array
Joint velocities	Axis-specific computed velocity in radians per seconds (axis 1 to 7). The velocity is calculated as the difference between the reading of two consecutive positions every 10 milliseconds (100 Hz).	8	7	Numeric array
Joint torques	Measured external acting torques, in Newton-meter, without the component resulting from the weight of the robot and mass inertias during motion (axis 1 to 7)	15	7	Numeric array
Cartesian position	End-effector Cartesian actual position in millimeters (X, Y, Z)	22	3	Numeric array
Cartesian orientation	End-effector Cartesian actual orientation in radians (A, B, C)	25	3	Numeric array
Cartesian forces	External Cartesian forces, in Newtons, acting on the end-effector (X, Y, Z)	28	3	Numeric array
Cartesian torques	External Cartesian torques, in Newton-meter, acting on the end-effector (A, B, C)	31	3	Numeric array
Last error	Last registered error code. See Errors	34	1	Boolean
Has fired condition	Whether motion has terminated due to a break condition	35	1	Boolean
Is ready to move	Whether the robot is ready for motion. A true value does not necessarily mean that the brakes are open and that the robot is under servo control	36	1	Boolean
Has active motion	Whether the robot is active. It does not provide any information on whether the robot is currently in motion (a false value does not necessarily mean that the robot is stationary)	37	1	Boolean

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Enumerations

Communication modes

Warning

Periodical communication mode is not currently implemented

Code	Description
11	On-demand: Enable communication only when necessary (when requested by the external control workstation)
12	Periodical: Enable continuous communication at periodic intervals

Control interfaces

Code	Description
31	Standard: Discontinuous (blocking or non-blocking) motion execution
32	Servo motions (Servoing): Non-deterministic, soft real-time motions

Control modes

Code	Description
41	Position controller: Execute the specified path with the maximum possible positional accuracy and without path deviation
42	Axis-specific impedance controller: Virtual spring damper system with configurable values for stiffness and damping for each axis (joint)
43	Cartesian impedance controller: Virtual spring damper system with configurable values for stiffness and damping. This allows the robot to react in a compliant manner to external influences
44	Cartesian impedance controller with overlaid force oscillation: Special form of the Cartesian impedance controller. In addition to the compliant behavior, constant force setpoints and sinusoidal force oscillations can be overlaid

Execution types

Code	Description
51	Asynchronous: Next program line is executed directly after the motion command is sent (non-blocking)
52	Synchronous: Motion commands are sent in steps to the real-time controller and executed (blocking)

Motion types

Code	Description
21	Point-to-point motion (PTP): Executes a point-to-point motion to the end point
22	Linear motion (LIN): Executes a linear motion to the end point
23	Linear relative motion (LIN_REL): Executes a linear motion relative to the end position of the previous
24	Circular motion (CIRC): Executes a circular motion

Errors

Code	Description
-10	No error: No error. This is not a guarantee that there are no errors
-11	Value error: An operation or function receives an argument that has the right type but an inappropriate value
-12	Invalid joint: Joint subscript is out of range
-13	Synchronous motion: Synchronous motion command execution failed
-14	Asynchronous motion: Asynchronous motion command execution failed
-15	Validation for impedance: Validation of the load model for impedance control to use servo motions has failed
-16	Invalid configuration: The robot has been configured to work with incompatible control settings