Failed to synchronously read the present position of 39 dynamixel

Hello everyone

DYNAMIXEL Actuator

dynamixel XH430-V350-R

Issue Description

I used 39 dynamixel actuators on a snake like robot and wanted to read their present position and velocity. However, when using the bulk or sync commands in the Python SDK to read data, I always returned “There is no status packet!” and "groupsyncread getdata failed“

I tried a baud rate of 1000000,51200 and 115200 and changed the serial port latency timer to adapt to a higher baud rate, but none of these methods worked.
Thanks for reading, any suggestions/help are greatly appreciated!

Additional Information/Attachments

Are there any communication problems when there are few Dynamixels?
Check whether there is no problem in operation with the provided example.

If there are many Dynamixels, it may be a power-related problem.
Check the voltage of Dynamixel, which is far from the power supply.