I can't connect to my Dynamixel servo : "void_dxl"

Hi !

I have the Dynamixel module (V1 I think). I upgraded this module with the firmware version 0.5.1. I connected my Dynamixel servo MX-28 to this module, then I connected a power supply (12V 5A) to the luos network thanks to the power plug module. But when I type the command robot.modules, just void_dxl appear instead of my_dxl_1. However my servo work well with the Robot + software.

I think I don’t really understand how this module work. Can you help me?


  • USB module : V0.0.2 on a Rev 0.2.1
  • Dxl module : Rev 0.2.0
  • Dynamixel servo : MX-28
  • firmware version : 0.5.1

I check the documentation and it’s missing some informations. We will add it as soon as possible.

Dynamixel boards dynamicaly create modules for each detected motors linked to it. This detection is performed at startup of the module (when the blue light is on).
There is 2 different firmwares for Dynamixel modules V1 and V2. They represent the revision of the robotis protocol used by the motor.

:warning: some motors can use different protocol depending on their production date.

If no motor is detected, a void_dxl module appear. This void module allow you to retry the dynamixel detection using :

To be detected the Dynamixel motor need to use a baudrate of 1 000 000 and to have an ID between 1 and 30.

@Theo : can you check your motor protocol revision, baudrate, and ID ?

Okay thank you !
Actually my Dynamixel motor had the bad baudrate, I changed it to 1 000 000 and now the module detect it. But nothing happens when I try to control it. However, according to Robotis, my Dynamixel work with the protocol 1.0, is there a way to check?

By default your motor is probably in compliant mode. In compliant mode the motor driver of the dynamixel is not enabled.
Before any movement you should do :
robot.dxl_1.compliant = False

It works :grinning: !
Thank you very much for your support !

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