Data Sheet

1/11/2018 XL430-W250
http://support.robotis.com/en/product/actuator/dynamixel_x/xl_series/xl430-w250.htm 9/15
Unit 20[ms]
Range
0 Deactivate Bus Watchdog Function, Clear Bus Watchdog Erro
1 ~ 127 Activate Bus Watchdog
-1 Bus Watchdog Error Status
The Bus Watchdog function monitors the communication interval (time) between the controller and Dynamixel when Torque Enable (64) is '1'.
If the measured communication interval (time) is larger than Bus Watchdog (98), the Dynamixel will be stopped. Bus Watchdog (98) will be changed to '-1' (Bus Watchdog Error).
If the Bus Watchdog Error screen appears, the Goal Value (Goal PWM(100), Goal Current(102), Goal Velocity(104), Goal Position(116)) will be changed to read-only property.
Therefore, when a new value is written to the Goal Value, a Range Error will be returned via the Status packet.
If the value of Bus Watchdog (98) is changed to '0', Bus Watchdog Error will be cleared.
Note: For details of Range Error, please refer to the protocol of the e-Manual.
The following are examples of the operation of the Bus Watchdog function.
① After setting the operating mode (11) to speed control mode, change the Torque Enable (64) to '1'.
② If '50' is written in the Goal Velocity (104), the Dynamixel will rotate in CCW direction.
③ Change the value of Bus Watchdog (98) to '100' (2,000 [ms]). (Activate Bus Watchdog Function)
④ If no instruction packet is received for 2,000 [ms], the Dynamixel will stop. When it stops, the Profile Acceleration (108) and Profile Velocity (112) are applied as '0'.
⑤ The value of Bus Watchdog (98) changes to '-1' (Bus Watchdog Error). At this time, the access to the Goal Value will be changed to read-only.
⑥ If '150' is written to the Goal Velocity (104), Range Error will be returned via Status Packet.
⑦ If the value of Bus Watchdog (98) is changed to '0', Bus Watchdog Error will be cleared.
⑧ If “150” is written in the Goal Velocity (104), the Dynamixel will rotate in CCW direction.
Goal PWM (100)
In case of PWM Control Mode, both PID controller and Feedforward controller are deactivated while Goal PWM(100) value is directly controlling the motor through an Inverter. In other control modes, this
value is used to limit PWM value. This value cannot exceed PWM Limit(36). Please refer to the Gain section in order to see how Goal PWM(100) affects to different control modes.
Values Description
Range -PWM Limit(36) ~ PWM Limit(36) Initial Value of PWM Limit(36) : ‘885’
Goal Velocity (104)
In case of Velocity Control Mode, Goal Velocity(104) can be used to set a target velocity. This value cannot exceed Velocity Limit(44). For now, Goal Velocity(104) is used for target velocity, but this value is
not used to limit the velocity.
Values Description
Unit 0.229[RPM] All velocity related Data uses the same unit
Range -Velocity Limit(44) ~ Velocity Limit(44) -
Note1) : The maximum velocity and maximum torque of Dynamixel is affected by supplying voltage. Therefore, if supplying voltage changes, so does the maximum velocity. This manual complies with
recommended supply voltage.
Note2) : If Profile Acceleration(108) and Goal Velocity(104) are modified simultaneously, modified Profile Acceleration(108) will be used to process Goal Velocity(104).
Profile Acceleration (108)
The acceleration of Profile can be set with this value. Profile Acceleration(108) can be used in all control modes except Torque Control Mode. Profile Acceleration(108) cannot exceed Acceleration Limit(40).
For more details, please refer to the Profile Velocity(112).
Values Description
Unit 214.577[Rev/min2] All acceleration related Data uses the same unit,
Range 0 ~ Acceleration Limit(40) The value '0' on Profile Acceleration(108) means infinite acceration.
Profile Velocity (112)
The Maximum velocity of Profile can be set with this value. Profile Velocity(112) can be used in all control modes except Torque Control Mode and Velocity Control Mode. Profile Velocity(112) cannot exceed
Velocity Limit(40). Velocity Control Mode only uses Profile Acceleration(108) instead of Profile Velocity(112).
Values Description
Unit 0.229[RPM] All velocity related Data uses the same unit
Range 0 ~ Velocity Limit(44) If Profile Velocity(112) is set to ‘0’, it stands for infinite velocity.
The Profile is an acceleration/deceleration control method to reduce vibration, noise and load of the motor by controlling dramatically changing velocity and acceleration. It is also called Velocity Profile as it
controls acceleration and deceleration based on velocity. Dynamixel provides 4 different types of Profile. The following explains 4 Profiles and how to select them. Profiles are usually selected by a
combination of Profile Velocity(112) and Profile Acceleration(108). Triangular and Trapezoidal Profiles exceptionally consider total travel distance(ΔPos, the distance difference between target position and
current position) as an additional factor. For convenience, Profile Velocity(112) is abbreviated to V
PRFL
and Profile Acceleration(108) is abbreviated to V
PRFL
. 'X' stands for "Don't Care" case.
When given Goal Position(116), Dynamixel's profile creates target velocity trajectory based on current velocity(initial velocity of the Profile). When Dynamixel receives updated target position from a new Goal
Position(116) while it is moving toward the previous Goal Position(116), velocity smoothly varies for the new target velocity trajectory. Maintaining velocity continuity while updating target velocity trajectory is