Red LED on Dynamixel Shield

Issue:

Hi there,

I want to control two XL-430-250-T servos using a Dynamixel Shield with Arduino Mega 2560 Rev3.

The servos are daisy chained with TTL cable. The Arduino gets power from its own USB port. The shield gets power from a 12V Power Supply connected to its green terminal using a barrel jack adapter with correct polarity and the associated jumper on the shield board removed.

The Arduino itself works and I can download and run code. However, when I power-up the shield, a small LED turns red immediately and stays red. I am unable to scan the servos via the Dynamixel Wizard, despite specifying the correct port (COM5 on USB), protocol (2) and default ID (1).

I also tried connecting the power supply to Arduino itself and putting back the jumper, to no avail. The red LED is still on.

Please advise. Thank you!


DYNAMIXEL Servo:

XL-430-W250-T


DYNAMIXEL Controller:

Dynamixel Shield


Software Interface:

DynamixelShield, Dynamixel2Arduino