About gRPC

//ParametricRobotControlService provides an interface for simulating/controlling supported robots through GRPC.
service ParametricRobotControlService {
 //Step 1: Setup the simulation/control environment.
  rpc SetupRobot (SetupRobotRequest) returns (SetupRobotReply);
  //Step 2: Define a task to be processed or simulated.
  rpc AddRobotTask (AddRobotTaskRequest) returns (AddRobotTaskReply);
  //Step 3: Subscribe to the feedback coming from the simulation/control environment.
  //The server keeps a robot set up only while this stream is open: when the stream ends
  //(the client cancels it, disposes its channel, quits or crashes) the robot is removed and
  //its driver disconnected within about a second. A new SetupRobot with the same client_id
  //ends the previous stream, so subscribe again after every SetupRobot.
  rpc SubscribeRobotFeedback (SubscribeRobotFeedbackRequest) returns (stream RobotFeedback);
  //Step 4: Request a simulation update, to be either provided directly or written to the feedback stream.
  //The omit_variables request flag skips the global variable map in the reply (which otherwise
  //carries every connected robot's variables), keeping state polls small for visualization-only clients.
  rpc GetSimulatedRobotState (GetSimulatedRobotStateRequest) returns (RobotState);
  //Optional: Set a variable on the robot. Always returns the current variables of all connected robots.
  rpc UpdateVariable (UpdateVariableRequest) returns (UpdateVariableReply);
  //Optional: Retrieve the resolved robot definition plus its live state (settings,
  //variables, axis position, tool/flange frames, visualization transformations) for
  //any robot that has already been set up. With exclude_geometry, the reply is cheap
  //enough for high-frequency polling (30-60 Hz), e.g. for machine monitoring.
  rpc GetRobotData (GetRobotDataRequest) returns (GetRobotDataReply);
  //Optional: Ping the controller.
  rpc SendPing (Ping) returns (Ping);
}

//ParametricRobotControlLibraryService (prc_library.proto) describes what this PRC installation can set up.
service ParametricRobotControlLibraryService {
  //Every preset robot, every driver with its settings schema and every preset external axis,
  //so a client can offer a robot setup wizard without a copy of the library.
  rpc DescribeLibrary (DescribeLibraryRequest) returns (DescribeLibraryReply);
}

//JointTarget contains the target position of the robot in joint space, as well as the speed and acceleration of the robot.
message JointTarget{
    //The target position of the robot in joint space.
    repeated float axis_values = 1;
    //The speed of the robot, either one value per axis or a single value for all.
    repeated float speed = 2;
    //The acceleration of the robot, either one value per axis or a single value for all.
    repeated float acceleration = 3;
    //The position of any external axes of the robot.
    repeated float external_axis_values = 4;
}

//CartesianTarget contains the position defined as a CartesianPosition and addds information relating to the posture, speed, acceleration of the robot, as well as of its external axes.
message CartesianTarget{
    //The CartesianPosition of the target.
    CartesianPosition position = 1;
    //The posture of the robot.
    string posture = 2;
    //The speed of the robot, either one value per axis or a single value for all.
    repeated float speed = 3;
    //The acceleration of the robot, either one value per axis or a single value for all.
    repeated float acceleration = 4;
    //The position of any external axes of the robot.
    repeated float external_axis_values = 5;
}

//CartesianPosition uses one of three definitions to define a Cartesian position, either as a matrix, through Euler values, or a coordinate system.
message CartesianPosition{
    //The frame, defined either as matrix, Euler values, or coordinate system.
    oneof frame {
        Matrix4x4 matrix = 1;
        Euler euler = 2;
        CoordinateSystem cs = 3;
    }
    //Only ABSOLUTE is supported: a target is expressed in its motion group's base, a TCP relative to the flange. RELATIVE and PARENT are refused with an error.
    CartesianReference reference = 4;
    //Not used: PRC ignores a parent sent with a position.
    Matrix4x4 parent = 5;
}

grpcurl -cacert PRCServerCertificate.pem 127.0.0.1:5001 list
grpcurl -cacert PRCServerCertificate.pem 127.0.0.1:5001 describe ParametricRobotControlService