[AkashKrishna]

I was trying out the MatlabAPI to test keyboard input for simulated robot Control. I was getting

"No public property 'TIMEOUT' for class 'Robolink'."

error when implementing the python version in Matlab. Before running the below code, a robot must be in the Station in RoboDK. I use the latest version of RoboDK v5.8.1.24728 and Matlab R2024b. 

Code:

% Initialize RoboDK API
RDK = Robolink();

% Get a robot
robot = RDK.Item('', RDK.ITEM_TYPE_ROBOT);
if ~robot.Valid()
    disp('No robot in the station. Load a robot first, then run this program.');
    pause(5);
    error('No robot in the station!');
end

disp(['Using robot: ', robot.Name()]);
disp('Use the arrows (left, right, up, down), Q and A keys to move the robot');
disp('Note: This works on console mode only, you must run the MATLAB file separately');

% Define keypress callback function
function keyPressCallback(~, event, robot)
    move_direction = [0, 0, 0];
    switch event.Key
        case 'leftarrow'
            disp('arrow left (Y-)');
            move_direction = [0, -1, 0];
        case 'rightarrow'
            disp('arrow right (Y+)');
            move_direction = [0, 1, 0];
        case 'uparrow'
            disp('arrow up (X-)');
            move_direction = [-1, 0, 0];
        case 'downarrow'
            disp('arrow down (X+)');
            move_direction = [1, 0, 0];
        case 'q'
            disp('Q (Z+)');
            move_direction = [0, 0, 1];
        case 'a'
            disp('A (Z-)');
            move_direction = [0, 0, -1];
    end

    % Make sure that a movement direction is specified
    if norm(move_direction) <= 0
        return;
    end

    % Calculate the movement in mm according to the movement speed
    xyz_move = move_direction * 10; % move_speed;
    disp(['xyz_move: ', mat2str(xyz_move)]);

    % Get the robot joints
    robot_joints = robot.Joints();
    if isempty(robot_joints)
        disp('Failed to retrieve robot joints.');
        return;
    end
    disp(['robot_joints: ', mat2str(robot_joints)]);

    % Get the robot position from the joints (calculate forward kinematics)
    robot_position = robot.SolveFK(robot_joints);
    if isempty(robot_position)
        disp('Failed to calculate robot position.');
        return;
    end
    disp(['robot_position: ', mat2str(robot_position)]);

    % Get the robot configuration (robot joint state)
    robot_config = robot.JointsConfig(robot_joints);
    if isempty(robot_config)
        disp('Failed to retrieve robot configuration.');
        return;
    end
    disp(['robot_config: ', mat2str(robot_config)]);

    % Calculate the new robot position
    new_robot_position = transl(xyz_move(1), xyz_move(2), xyz_move(3)) * robot_position;
    disp(['new_robot_position: ', mat2str(new_robot_position)]);

    % Calculate the new robot joints
    new_robot_joints = robot.SolveIK(new_robot_position);
    if isempty(new_robot_joints)
        disp('No robot solution!! The new position is too far, out of reach or close to a singularity');
        return;
    end
    disp(['new_robot_joints: ', mat2str(new_robot_joints)]);

    % Calculate the robot configuration for the new joints
    new_robot_config = robot.JointsConfig(new_robot_joints);
    if isempty(new_robot_config)
        disp('Failed to retrieve new robot configuration.');
        return;
    end
    disp(['new_robot_config: ', mat2str(new_robot_config)]);

    try
        % Move the robot joints to the new position
        robot.MoveL(new_robot_joints);
    catch ME
        disp(['Error moving robot: ', ME.message]);
    end

    % Process any pending callbacks
    drawnow;
end

% Set up figure to capture keypress events
fig = figure('KeyPressFcn', @(src, event) keyPressCallback(src, event, robot));

% Keep the script running without blocking indefinitely
while ishandle(fig)
    drawnow;
end

I used the try and catch method to handle the exception, but the robot does not move. 

The only way the above code works and the robot moves is when under Matlab/RoboLinkItem.m, I comment the Timeout lines under the function WaitMove():

Code:

        function WaitMove(this, timeout)
            % Waits (blocks) until the robot finished its move.
            % In  1 (optional) timeout -> Max time to wait for robot to finish its movement (in seconds)
            if nargin < 2
                timeout = 300;
            end

            this.link.check_connection();
            command = 'WaitMove';
            this.link.send_line(command);
            this.link.send_item(this);
            this.link.check_status();
            
            % Commenting the following lines
            %set(this.link.COM, 'Timeout', timeout);
            %this.link.check_status();
            %set(this.link.COM, 'Timeout', this.link.TIMEOUT);
        end

But then, when I register a very frequent keypresses, I get a Unknown error as follows:

Code:

Unknown error
Error using Robolink/check_status (line 139)
Unknown error

Error in RobolinkItem/Joints (line 639)
            this.link.check_status();
            ^^^^^^^^^^^^^^^^^^^^^^^^
Error in keypress>keyPressCallback (line 50)
    robot_joints = robot.Joints();
                  ^^^^^^^^^^^^^^
Error in keypress>@(src,event)keyPressCallback(src,event,robot) (line 105)
fig = figure('KeyPressFcn', @(src, event) keyPressCallback(src, event, robot));
                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Error using keypress>keyPressCallback (line 101)
Error while evaluating Figure KeyPressFcn.

The Unknown error is more of an warning than an error, as the robot jitters/jerks and continues with next keypresses. 

Can I request a solution rather than this workaround?

[Albert]

What robots are you trying to use? Can you share you RoboDK project file? Are you using the driver? If so, can you share the connection log?

Can you provide us with the Matlab .m file to reproduce this issue?