- ROBOTIS Dynamixel RX-28 User's Manual
DYNAMIXEL 
RX-28 
The meanings of each packet byte definition are as the following. 
0XFF 0XFF  The two 0XFF bytes indicate the start of the packet. 
ID  The unique ID of the Dynamixel unit returning the packet. The initial value is set to 1. 
LENGTH  The length of the packet where its value is “Number of parameters (N) + 2” 
ERROR  The byte representing errors sent from the Dynamixel unit. The meaning of each bit is 
as the following. 
Bit Name  Details 
Bit 7  0  - 
Bit 6  Instruction Error
Set to 1 if an undefined instruction is sent or an action 
instruction is sent without a Reg_Write instruction. 
Bit 5  Overload Error
Set to 1 if the specified maximum torque can't control the 
applied load.   
Bit 4  Checksum Error Set to 1 if the checksum of the instruction packet is incorrect. 
Bit 3  Range Error  Set to 1 if the instruction sent is out of the defined range. 
Bit 2 
Overheating 
Error 
Set to 1 if the internal temperature of the Dynamixel unit is 
above the operating temperature range as defined in the 
control table. 
Bit 1 
Angle Limit 
Error 
Set as 1 if the Goal Position is set outside of the range 
between CW Angle Limit and CCW Angle   
Limit. 
Bit 0 
Input Voltage 
Error 
Set to 1 if the voltage is out of the operating voltage range as 
defined in the control table. 
PARAMETER0…N  Used if additional information is needed. 
CHECK SUM  The computation method for the ‘Check Sum’ is as the following. 
Check Sum = ~ (ID + Length + Instruction + Parameter1 + ... Parameter N) 
If the calculated value is larger than 255, the lower byte is defined as the checksum 
value. ~ represents the NOT logic operation. 
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