Monitor the state of the robot

Follow the robot mode, the program, the stops, the safety status and the connection of a UR cobot in C# or Python.

Which way to choose
Prerequisites
Example
Connection
What to read next

This article shows how to follow the state of a Universal Robots cobot from a PC, in C# or Python: robot mode, power, program, protective and emergency stops, safety status and connection. It compares the interfaces and gives a program that prints each change.

Which way to choose

Way	Frequency	What it gives
Primary Interface	10 Hz, events	`RobotModeData`: robot mode, power, program running or paused, stops, speed fraction. `MasterboardData.Safetymode`
RTDE	Up to 500 Hz	`RobotMode`, `SafetyMode`, `SafetyStatus`, `RuntimeState`, `RobotStatusBits`, `SpeedScaling`, as numbers
Dashboard Server	When you ask	`GetRobotMode()`, `GetProgramState()` with the name of the program, `GetSafetyStatus()`, `IsInRemoteControl()`, `GetOperationalMode()`
REST API	When you ask	`GetProgramState()` on PolyScope X

The Primary Interface gives typed values and events, with no setup. RTDE gives the same states as numbers, faster: see the RTDE guide of Universal Robots for their values. The Dashboard Server adds the name of the loaded program and the remote control.

Prerequisites

The services Primary Client Interface and Dashboard Server are enabled: see Prepare the robot.
No remote control is needed to read the state.

Example

The program prints the robot mode package when it changes, the safety status when it is not normal, and the loaded program every 2 s, until the connection is lost.

using UnderAutomation.UniversalRobots;
using UnderAutomation.UniversalRobots.Common;
using UnderAutomation.UniversalRobots.PrimaryInterface;

class HowToMonitorState
{
  static void Main(string[] args)
  {
    
    var robot = new UR();

    // Primary Interface and Dashboard Server
    robot.Connect("192.168.0.1");

    // Robot mode package, 10 times per second: print the changes only
    string last = null;
    robot.PrimaryInterface.RobotModeDataReceived += (sender, e) =>
    {
      string state =
        $"mode={e.RobotMode} powered={e.RobotPowerOn} running={e.ProgramRunning} " +
        $"paused={e.ProgramPaused} protective stop={e.ProtectiveStopped} " +
        $"emergency stop={e.EmergencyStopped} speed={e.TargetSpeedFraction:P0}";

      if (state != last) Console.WriteLine(DateTime.Now.ToString("HH:mm:ss.fff") + " " + state);
      last = state;
    };

    // Safety status, in the masterboard package
    robot.PrimaryInterface.MasterboardDataReceived += (sender, e) =>
    {
      if (e.Safetymode != SafetyStatus.Normal) Console.WriteLine("Safety: " + e.Safetymode);
    };

    // Lost connection: the property becomes false, there is no event
    while (robot.PrimaryInterface.Connected)
    {
      // Loaded program and its state, every 2 s
      var program = robot.Dashboard.GetProgramState();
      if (program.Succeed) Console.WriteLine(program.Value.Name + ": " + program.Value.State);

      Thread.Sleep(2000);
    }

    Console.WriteLine("Connection lost");
    
  }
}

The events run in a thread of the SDK. Keep them short, and copy the values you need to your own thread.

Connection

PrimaryInterface.Connected and Rtde.Connected become false when the connection is lost: no event is raised and the SDK does not reconnect. Poll them, and call Connect again. InternalErrorOccured is raised for the errors of the background threads.

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Monitor the state of the robot

Which way to choose

Prerequisites

Example

Connection

What to read next