Realtime UR connection

[filipejsbrandao]

I'm trying to get the robot actual TCP position from a UR robot from grasshopper using robots. I have seen some previous posts here which use the URReal class which is deprecated. So I tried to implement it using the URRealTimeDataExchange class. I managed to connect to the robot and get some values in return, but all the values are always 0.

For instance, the code below returns a array of 6 values in the TCPPosition output: [0,0,0,0,0,0]
I have to mention that I currently don't have access to the robot, so I'm testing this on a VM. Yet, it should be the same. What am I missing here?

`private void RunScript(
string robotIP,
bool getPosition,
ref object TCPPosition,
ref object LogMessages)
{
// Output variables
TCPPosition = null;
List logs = new List();

    // Check if the connection should be triggered
    if (getPosition)
    {
        try
        {
            // List of variables to request from the robot
            List<string> variables = new List<string> { "actual_TCP_pose" };

            // Create a new instance of the URRealTimeDataExchange class
            using (var urRTDE = new Robots.URRealTimeDataExchange(robotIP, variables))
            {
                // Read data from the robot
                urRTDE.ReadOutputs();

                // Retrieve the TCP pose data
                foreach (var output in urRTDE.Outputs)
                {
                    if (output.Name == "actual_TCP_pose")
                    {
                        TCPPosition = output.Values; // Store the TCP position values
                        break;
                    }
                }

                // Add log messages
                logs.AddRange(urRTDE.Log);
            }
        }
        catch (Exception ex)
        {
            // Handle exceptions and log errors
            logs.Add($"Error: {ex.Message}");
        }
    }
    else
    {
        logs.Add("Connection not triggered.");
    }

    // Output the logs
    LogMessages = logs;
}`

[visose]

I would change this so that the URRealTimeDataExchange instance is a field rather than a local variable inside RunScript. Initialize it only once and run the component on a loop with a timer, without reinitializing it on every call to RunScript.

[filipejsbrandao]

Thanks for the advice. I have done as you suggested but I'm still only getting [0,0,0,0,0,0] as TCP position. Here is how the code looks:

`public class Script_Instance : GH_ScriptInstance
{
// Persistent fields
private URRealTimeDataExchange urRTDE; // Persistent RTDE connection
private bool isConnected = false; // Connection status
private List lastTCPPosition; // Store last successful TCP position
private List logs = new List(); // Log messages

private void RunScript(string robotIP, bool connect, bool getUpdatedPosition, ref object TCPPosition, ref object LogMessages)
{
    // Output variables
    TCPPosition = lastTCPPosition; // Default to the last successful position
    logs.Clear();                  // Reset logs for each run

    // Handle connection logic
    if (connect)
    {
        if (!isConnected)
        {
            try
            {
                // Initialize connection if not already connected
                List<string> variables = new List<string> { "actual_TCP_pose" };
                urRTDE = new URRealTimeDataExchange(robotIP, variables);
                isConnected = true;
                logs.Add($"Connected to robot at {robotIP}");
            }
            catch (Exception ex)
            {
                logs.Add($"Error connecting to robot: {ex.Message}");
            }
        }

        // If connected and an update is requested, fetch the TCP position
        if (isConnected && getUpdatedPosition)
        {
            try
            {
                urRTDE.ReadOutputs();

                // Retrieve the `actual_TCP_pose` data
                foreach (var output in urRTDE.Outputs)
                {
                    if (output.Name == "actual_TCP_pose")
                    {
                        lastTCPPosition = new List<double>(output.Values); // Update stored position
                        TCPPosition = lastTCPPosition;                    // Output updated position
                        logs.Add("TCP position updated successfully.");
                        break;
                    }
                }

                // Log messages from URRealTimeDataExchange
                logs.AddRange(urRTDE.Log);
            }
            catch (Exception ex)
            {
                logs.Add($"Error reading robot data: {ex.Message}");
            }
        }
    }
    else
    {
        // Disconnect the robot if `connect` is false
        if (isConnected)
        {
            urRTDE?.Dispose();
            urRTDE = null;
            isConnected = false;
            logs.Add("Disconnected from robot.");
        }
        else
        {
            logs.Add("Robot already disconnected.");
        }
    }

    // Output the logs
    LogMessages = logs;
}

// Destructor for proper cleanup
~Script_Instance()
{
    urRTDE?.Dispose();
}

}`

Thanks

[filipejsbrandao]

I think I found out what the problem is. If I send a program using the Robots Remote Connection component I have to reinitialise the connection to be able to get the values. So I imagine the remote connection component also uses RTDE to send programs to the robot..
Thanks!