Registers & variables

Read and write numeric, position, and string registers, system variables, and perform batch operations via CGTP.

Read a variable
Supported types
Read and Write registers
Batch variables
Complete example
API reference

CGTP lets you read and write any system variable, program variable, and register (numeric, position, string) on your Fanuc robot.

Read a variable

ReadVariable returns a typed CgtpVariableValue with automatic parsing:

FanucRobot robot = new FanucRobot();
robot.Connect("192.168.0.1");
// Read as typed value
CgtpVariableValue var1 = robot.Cgtp.ReadVariable("$RMT_MASTER");
int intVal = var1.IntegerValue;
CgtpVariableType type = var1.Type;

// Read as raw string
string raw = robot.Cgtp.ReadVariableAsString("$MCR.$GENOVERRIDE");

// Write a variable
robot.Cgtp.WriteVariable("$RMT_MASTER", 1);
robot.Cgtp.WriteVariable("$MCR.$GENOVERRIDE", 50.0);

// Program-scoped variables (Karel)
CgtpVariableValue karelVar = robot.Cgtp.ReadVariable("my_variable", progName: "MY_KAREL");
robot.Cgtp.WriteVariable("my_variable", 42, progName: "MY_KAREL");
}
}

Click to see the full code

Supported types

The variable type is auto-detected. You can access the appropriate typed property:

Type	Property
Integer	`IntegerValue`
Real	`RealValue`
Boolean	`BooleanValue`
String	`StringValue`
CartesianPosition	`CartesianPositionValue`
JointPosition	`JointPositionValue`
Vector	`VectorValue`
Config	`ConfigurationValue`

Read and Write registers

FanucRobot robot = new FanucRobot();
robot.Connect("192.168.0.1");
// Numeric registers
NumericRegisterWithComment reg = robot.Cgtp.ReadNumericRegisterWithComment(1);
Console.WriteLine($"R[1] = {reg.RealValue}, Comment: {reg.Comment}");
NumericRegisterWithComment[] allRegs = robot.Cgtp.ReadNumericRegistersWithComment();
robot.Cgtp.WriteNumericRegisterAsDouble(5, 123.45);
robot.Cgtp.WriteNumericRegisterAsInteger(5, 100);

// Position registers
PositionRegisterWithComment posReg = robot.Cgtp.ReadPositionRegisterWithComment(1);
robot.Cgtp.WritePositionRegisterAsCartesian(1, new CartesianPosition(100, 200, 300, 0, 90, 0));
robot.Cgtp.WritePositionRegisterAsJoint(1, new JointsPosition { J1 = 0, J2 = 0, J3 = 0, J4 = 0, J5 = 0, J6 = 0 });

// String registers
StringRegisterWithComment[] allStr = robot.Cgtp.ReadStringRegistersWithComment();
robot.Cgtp.WriteStringRegister(1, "Hello from CGTP");
}
}

Click to see the full code

Batch variables

Read or write multiple registers and variables in a single HTTP request:

FanucRobot robot = new FanucRobot();
robot.Connect("192.168.0.1");
// Create a batch
var batch = new CgtpBatchVariables();
batch.AddNumericRegister(1);
batch.AddNumericRegister(2);
batch.AddStringRegister(1);
batch.AddPositionRegister(1);
batch.AddVariable("$RMT_MASTER");
batch.AddVariable("$MCR.$GENOVERRIDE");

// Read all at once
CgtpBatchReadResult result = robot.Cgtp.ReadBatchVariables(batch);

// Write batch with values
var writeBatch = new CgtpBatchVariables();
writeBatch.AddNumericRegisterAsReal(1, "Speed", 50.0);
writeBatch.AddNumericRegisterAsInteger(2, "Counter", 0);
writeBatch.AddStringRegisterWithValue(1, "Status", "Running");
robot.Cgtp.WriteBatchVariables(writeBatch);
}
}

Click to see the full code

Complete example

using UnderAutomation.Fanuc;
using UnderAutomation.Fanuc.Common;
using UnderAutomation.Fanuc.Cgtp;
using UnderAutomation.Fanuc.Cgtp.BatchVariables;

public class CgtpRegistersVariables
{
  public static void Main()
  {
    FanucRobot robot = new FanucRobot();

    ConnectionParameters parameters = new ConnectionParameters("192.168.0.1");
    parameters.Cgtp.Enable = true;

    robot.Connect(parameters);

    
    // --- Read variables ---
    CgtpVariableValue var = robot.Cgtp.ReadVariable("$RMT_MASTER");
    int intVal = var.IntegerValue;
    CgtpVariableType type = var.Type;

    // Read as raw string
    string raw = robot.Cgtp.ReadVariableAsString("$MCR.$GENOVERRIDE");

    // Write a variable
    robot.Cgtp.WriteVariable("$RMT_MASTER", 1);
    robot.Cgtp.WriteVariable("$MCR.$GENOVERRIDE", 50.0);

    // --- Program-scoped variables ---
    CgtpVariableValue karelVar = robot.Cgtp.ReadVariable("my_variable", progName: "MY_KAREL");
    robot.Cgtp.WriteVariable("my_variable", 42, progName: "MY_KAREL");

    // --- Numeric registers ---
    NumericRegisterWithComment reg = robot.Cgtp.ReadNumericRegisterWithComment(1);
    robot.Cgtp.WriteNumericRegisterAsDouble(5, 123.45);
    robot.Cgtp.WriteNumericRegisterAsInteger(5, 100);

    // --- Position registers ---
    PositionRegisterWithComment posReg = robot.Cgtp.ReadPositionRegisterWithComment(1);
    robot.Cgtp.WritePositionRegisterAsCartesian(1, new CartesianPosition(100, 200, 300, 0, 90, 0));
    robot.Cgtp.WritePositionRegisterAsJoint(1, new JointsPosition { J1 = 0, J2 = 0, J3 = 0, J4 = 0, J5 = 0, J6 = 0 });

    // --- String registers ---
    StringRegisterWithComment[] allStr = robot.Cgtp.ReadStringRegistersWithComment();
    robot.Cgtp.WriteStringRegister(1, "Hello from CGTP");

    // --- Batch read ---
    var batch = new CgtpBatchVariables();
    batch.AddNumericRegister(1);
    batch.AddNumericRegister(2);
    batch.AddStringRegister(1);
    batch.AddPositionRegister(1);
    batch.AddVariable("$RMT_MASTER");
    CgtpBatchReadResult result = robot.Cgtp.ReadBatchVariables(batch);

    // --- Batch write ---
    var writeBatch = new CgtpBatchVariables();
    writeBatch.AddNumericRegisterAsReal(1, "Speed", 50.0);
    writeBatch.AddNumericRegisterAsInteger(2, "Counter", 0);
    writeBatch.AddStringRegisterWithValue(1, "Status", "Running");
    robot.Cgtp.WriteBatchVariables(writeBatch);
    
  }
}

API reference

Class

CgtpVariableValue

C#Python

Represents the value of a controller variable with its data type.

Member	Type	Description
BooleanValue Property read only	bool	Value interpreted as a boolean (TRUE/FALSE).
CartesianPositionValue Property read only	CartesianPositionVariable	Value interpreted as a Cartesian position.
ConfigurationValue Property read only	Configuration	Value interpreted as a robot configuration.
IntegerValue Property read only	int	Value interpreted as an integer.
JointPositionValue Property read only	JointPositionVariable	Value interpreted as a joint position.
RealValue Property read only	double	Value interpreted as a double-precision floating-point number.
StringLength Property read only	int	Maximum string length if the variable type is String
StringValue Property read only	string	Raw string value of the variable
Type Property read only	CgtpVariableType	Data type of the variable
VectorValue Property read only	VectorVariable	Value interpreted as a 3D vector.
ToString() Method	string

Enum

CgtpVariableType

C#Python

Data types that can be returned when reading a controller variable.

Name	Value	Description
Boolean	18	Boolean value (TRUE or FALSE).
Byte	24	8-bit byte value.
CartesianPosition	2	Cartesian position (X, Y, Z, W, P, R with configuration).
Config	28	Robot configuration string.
Integer	16	32-bit integer value.
JointPose9	8601	Joint position with up to 9 axes.
JointPosition	9	Joint position (J1..J9).
Numeric	38	Numeric value that can be either integer or real.
POSITION	257	Full position type.
Real	17	Double-precision floating-point value.
Short	23	16-bit short integer value.
String	7936	String value. The actual type code encodes the maximum string length.
Vector	19	3D vector (X, Y, Z).
XYZWPR	256	XYZWPR position type.
XYZWPRExt	262	Extended XYZWPR position with additional axes.

Class

CgtpBatchVariables

C#Python

Collection of batch variables to read from or write to the controller in a single operation. Provides convenience methods to add typed variables.

Member	Type	Description
CgtpBatchVariables() Constructor
Count Property read only	int
IsReadOnly Property read only	bool
this[int] Property	ICgtpBatchVariable
Add(ICgtpBatchVariable) Method	void
AddNumericRegister(int) Method	CgtpNumericRegister	Add a numeric register for reading. The value and comment will be populated after a batch read. index : 1-based register index (R[index])
AddNumericRegisterAsInteger(int, string, int) Method	CgtpNumericRegister	Add a numeric register with an integer value and comment for writing. index : 1-based register index (R[index]) comment : Register comment (mandatory) value : Integer value to write
AddNumericRegisterAsReal(int, string, double) Method	CgtpNumericRegister	Add a numeric register with a real (double) value and comment for writing. index : 1-based register index (R[index]) comment : Register comment (mandatory) value : Real value to write
AddPositionRegister(int, int) Method	CgtpPositionRegister	Add a position register for reading. The position data will be populated after a batch read. index : 1-based register index (PR[index]) group : Motion group number (default 1)
AddPositionRegisterAsCartesian(int, CartesianPosition, int, string) Method	CgtpPositionRegister	Add a position register with a Cartesian position for writing. index : 1-based register index (PR[index]) position : Cartesian position to write group : Motion group number (default 1) comment : Optional comment. Null means no comment is written.
AddPositionRegisterAsJoint(int, JointsPosition, int, string) Method	CgtpPositionRegister	Add a position register with a joint position for writing. index : 1-based register index (PR[index]) position : Joint position to write group : Motion group number (default 1) comment : Optional comment. Null means no comment is written.
AddRange(IEnumerable<ICgtpBatchVariable>) Method	void	Add multiple variables at once.
AddStringRegister(int) Method	CgtpStringRegister	Add a string register for reading. The value and comment will be populated after a batch read. index : 1-based register index (SR[index])
AddStringRegisterWithValue(int, string, string) Method	CgtpStringRegister	Add a string register with a value and comment for writing. index : 1-based register index (SR[index]) comment : Register comment (mandatory) value : String value to write
AddVariable(string, string) Method	CgtpVariable	Add a generic variable for reading or writing. For system variables, leave `programName` null. Set the desired value on the returned object before performing a batch write. name : Full variable name (e.g. "$RMT_MASTER", "$MNUTOOL[1,1]") programName : Program name that owns the variable. Null for system variables.
Clear() Method	void
Contains(ICgtpBatchVariable) Method	bool
CopyTo(ICgtpBatchVariable[], int) Method	void
GetEnumerator() Method	IEnumerator<ICgtpBatchVariable>
IndexOf(ICgtpBatchVariable) Method	int
Insert(int, ICgtpBatchVariable) Method	void
Remove(ICgtpBatchVariable) Method	bool
RemoveAt(int) Method	void

Class

NumericRegisterWithCommentinherits NumericRegister

C#Python

Represents a numeric register with an associated comment.

Member	Type	Description
NumericRegisterWithComment() Constructor		Default constructor.
NumericRegisterWithComment(double, string) Constructor		Creates a numeric register with a real value and comment.
NumericRegisterWithComment(int, string) Constructor		Creates a numeric register with an integer value and comment.
NumericRegisterWithComment(string) Constructor		Creates a numeric register with a comment.
Comment Property	string	Comment associated with this register.
ToString() Method	string

Class

PositionRegisterWithCommentinherits PositionRegister

C#Python

Represents a position register with an associated comment.

Member	Type	Description
PositionRegisterWithComment() Constructor		Default constructor.
Comment Property	string	Comment associated with this position register.
Parse(string) Method static	PositionRegisterWithComment	Parses a position register with comment from its string representation.

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Registers & variables

Read a variable

Supported types

Read and Write registers

Batch variables

Complete example

API reference