DYNAMIXEL X-Series actuators include a Drive Mode setting (Control Table Address 10) that allows users to change how the motor interprets commands. Instead of changing the operating mode itself, Drive Mode modifies how commands behave, making it useful for tuning motion behavior or simplifying system design.

2.4.6 Drive Mode (10)

The Drive Mode (10) register configures how a DYNAMIXEL actuator executes commands. Each bit enables a specific behavior such as automatic torque activation, motion profile generation, or reversing the actuator’s rotation direction.

Bit	Item	Description
Bit 7 (0x80)	–	Unused, always 0
Bit 6 (0x40)	–	Unused, always 0
Bit 5 (0x20)	–	Unused, always 0
Bit 4 (0x10)	–	Unused, always 0
Bit 3 (0x08)	Torque On by Goal Update	[0] Execute command only when Torque Enable(64) = 1 [1] Execute command regardless of torque state. If torque is 0, the actuator automatically enables torque and executes the command.
Bit 2 (0x04)	Profile Configuration	[0] Velocity-based profile: motion generated using velocity [1] Time-based profile: motion generated based on time
Bit 1 (0x02)	–	Unused, always 0
Bit 0 (0x01)	Normal / Reverse Mode	[0] Normal Mode: CCW (Positive), CW (Negative) [1] Reverse Mode: CCW (Negative), CW (Positive)

Note: Torque On by Goal Update is available starting from firmware V46.

Note: When Bit 0 (Normal/Reverse Mode) is set to 1, the actuator’s rotation direction is inverted. This is useful when configuring symmetrical robot joints.

Several helpful features can be configured through Drive Mode bits, including Torque On by Goal Update, Profile Configuration, and Normal/Reverse Mode.

Below is a quick overview of what each does, how to enable it, and when it’s useful.

Torque On by Goal Update

Normally, a DYNAMIXEL actuator will only execute motion commands when Torque Enable(64) is already set to 1. If torque is disabled, the command is ignored.

When Torque On by Goal Update is enabled, sending a goal command automatically enables torque and executes the motion command, even if torque was previously off.

How to activate -

This feature is controlled by Drive Mode Bit 3 (0x08).

0 – Execute commands only if torque is already enabled

1 – Automatically enable torque when a goal command is received

Example (Drive Mode value):

Drive Mode = 0x08

This mode is helpful when:

You want to simplify command logic in scripts or teleoperation systems

Sending commands from high-level software (ROS, AI pipelines, etc.)

Reducing the need to manually toggle torque before each movement

It’s especially useful when quickly issuing commands during interactive control or testing.

Profile Configuration

DYNAMIXEL actuators generate motion profiles using Profile Velocity and Profile Acceleration. These profiles control how smoothly the motor accelerates and decelerates during movement.

Drive Mode allows users to choose between two types of profiles:

Velocity-based profile

Time-based profile

How to activate -

This feature is controlled by Drive Mode Bit 2 (0x04).

0 – Velocity-based profile

1 – Time-based profile

Example:

Drive Mode = 0x04

When to use each

Velocity-based Profile (default)

Movement is generated using maximum velocity and acceleration values.

Best for:

Robotics applications that need dynamic movement

Systems where speed control matters

Mobile robots and arms that respond to changing commands

Time-based Profile

Movement is executed over a specified time duration, regardless of distance.

Best for:

Synchronized multi-joint motion

Animations or demonstrations

Applications where movement should finish in a predictable amount of time

Normal / Reverse Mode

Normal/Reverse Mode changes the direction sign convention of the actuator.

Normally:

CCW rotation = positive value // CW rotation = negative value

When reversed:

CCW rotation = negative value // CW rotation = positive value

How to activate

This feature is controlled by Drive Mode Bit 0 (0x01).

0 – Normal Mode

1 – Reverse Mode

Example:

Drive Mode = 0x01

Reverse Mode is extremely useful when building symmetrical robot joints, such as:

Dual-arm robots

Humanoid shoulders

Parallel linkages

Mirrored joint mechanisms

Instead of rewriting control code, you can simply reverse the actuator’s direction in hardware settings.

Quick Summary

Feature	Bit	Purpose	Typical Use
Torque On by Goal Update	Bit 3	Automatically enables torque when a command is sent	Teleoperation, scripting, AI control
Profile Configuration	Bit 2	Choose velocity-based or time-based motion profiles	Smooth motion tuning
Normal / Reverse Mode	Bit 0	Invert actuator direction	Symmetrical robot joints