View Full Version : [Question(s)] Dynamixel SDK Samples fail on MX-28

08-27-2013, 03:36 PM
I have connected a MX-28 using USB2Dynamixel on Windows. I can set the goal position and read the current position using Dynamixel Wizard. However trying to do that same with their SDK samples fails with COMM_RXTIMEOUT (ReadFile returns 0 bytes read). Any ideas why this would be happening? Thanks

08-27-2013, 03:42 PM
Two reasons I can think of:
1) You're specifying the wrong COM port for the SDK.
2) You're using the wrong baud rate in the SDK.

08-27-2013, 04:56 PM
The COM port seems to be right. dxl_initialize failed when that was wrong. I am not too sure of the baud rate though. From the device management for the COM device, I see that the BPS is set to 9600. The default in the SDK was 1Mbps. After looking at the manual http://support.robotis.com/en/techsupport_eng.htm#product/auxdevice/interface/usb2dxl_manual.htm I changed the baudnum parameter to dxl_initialize to 207. Do you think this is still wrong ?

08-27-2013, 05:39 PM
Windows device manager says absolutely nothing about the servo settings and the baud rate it lists for the FT232RL rarely has any relationship to how the programs using it are actually configuring the COM port. All dynamixels except for the AX-series ship with a default baud rate of 57600 bps and unless there is a great deal of interference on the bus it usually changed using dynamixel wizard to 1Mbps (this is the default rate of the AX-series and RoboPlus Task).

08-27-2013, 06:01 PM
Thanks a million and Perfect timing too. I just found that there was a different baud rate being shown in the Dynamixel wizard and I was going to ask about that when you answered. It works now :-). Thanks again.