dynamixel torque controller does not move ax12 servo

edit

Hi,

I would like to get torque control running on an AX-12 (final goal is to get a zero torque controller, so that the axle can be moved freely with less friction than the torque_disable mode)

Using dynamixel_tutorial with one single AX-12 servo connected to ttyUSB0 (through a CM-5 in toss mode) I edited the dynamixel_joint_controllers.yaml to read

pan_controller:
controller:
    package: dynamixel_controllers
    module: join_torque_controller
    type: JointTorqueController
joint_name: pan_joint
joint_speed: 2.0
motor:
    id: 14
    init: 512
    min: 0
    max: 1023

and of course the spawner launch file to use this pan_controller.

Things start well, I can see the motor_state etc... but sending commands to the pan_controller/command topic will not move the motor at all (should move with non-null torques). I checked, speeds are well sent to the motor but it does not move. I also tested putting min and max to 0 for the position to get the "wheel" mode. torque_limit is high as well as speed_limit

motor moves nicely with the position controller but nothing happens with the torque controller

What do I do wrong ? Is it possible to control torque(speed) only on an AX-12 ?

thanks.