read_data_rt

This function reads the real-time output data from the robot controller. It retrieves the latest output structure containing motion, torque, and system states configured by set_rt_control_output.

Typically used inside a real-time loop after start_rt_control to continuously monitor joint positions, velocities, or external torques.

Definition
DRFLEx.h within class CDRFLEx, public section (line 597)

LPRT_OUTPUT_DATA_LIST read_data_rt() {
    return _read_data_rt(_rbtCtrlUDP);
};

Parameter
None

Return

Value	Description
LPRT_OUTPUT_DATA_LIST	Pointer to the structure containing all RT output data fields defined by get_rt_control_output_data_list.

Example

#include "DRFLEx.h"
#include <iostream>
#include <cstring>
using namespace DRAFramework;

int main() {
    CDRFLEx drfl;
    drfl.connect_rt_control("192.168.137.100", 12347);

    std::string version = "v1.0";
    float period = 0.001f;  // 1 msec
    int lossCount = 4;

    // Configure input/output streaming
    drfl.set_rt_control_input(version, period, lossCount);
    drfl.set_rt_control_output(version, period, lossCount);
    drfl.start_rt_control();

    // Real-time reading loop
    while (true) {
        auto data = drfl.read_data_rt();
        if (!data) continue;

        // Read key fields
        float jointPos[6];
        float jointVel[6];
        float jointTorque[6];

        memcpy(jointPos, data->actual_joint_position, sizeof(float) * 6);
        memcpy(jointVel, data->actual_joint_velocity, sizeof(float) * 6);
        memcpy(jointTorque, data->actual_joint_torque, sizeof(float) * 6);

        std::cout << "Joint 1 Pos: " << jointPos[0]
                  << "  Vel: " << jointVel[0]
                  << "  Torque: " << jointTorque[0] << std::endl;

        // Custom condition to break the loop
        if (jointPos[0] > 30.0f)
            break;

        // Sleep for the RT period
        std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }

    drfl.stop_rt_control();
    drfl.disconnect_rt_control();
    return 0;
}

In this example, the function continuously retrieves and prints the current joint position, velocity, and torque from the real-time stream.

Tips

• Always call this function after RT streaming is started using start_rt_control.

• The returned structure pointer updates every RT cycle — avoid holding it persistently.

• Use memcpy or direct indexing to copy data safely inside the loop.

• For visualization, store data into arrays or send to a logger in real time.