ROBOTIS e-Manual v1.31.30

Control Table consists of data regarding the current status and operation, which exists inside of Dynamixel. The user can control Dynamixel by changing data of Control Table via Instruction Packet.

EEPROM and RAM

Data in RAM area is reset to the initial value whenever the power is turned on while data in EEPROM area is kept once the value is set even if the power is turned off.

Note : Two's complement rule is followed to find the negative value in multi turn mode. For more information, please refer to the following link (Two's complement link).

Address

It represents the location of data. To read from or write data to Control Table, the user should assign the correct address in the Instruction Packet.

Access

Dynamixel has two kinds of data: Read-only data, which is mainly used for sensing, and Read-and-Write data, which is used for driving.

Initial Value

In case of data in the EEPROM Area, the initial values on the right side of the below Control Table are the factory default settings. In case of data in the RAM Area, the initial values on the right side of the above Control Tables are the ones when the power is turned on.

Highest/Lowest Byte

In the Control table, some data share the same name, but they are attached with (L) or (H) at the end of each name to distinguish the address. This data requires 16bit, but it is divided into 8bit each for the addresses (low) and (high). These two addresses should be written with one Instruction Packet at the same time.

It represents the Model Number.

It represents the firmware version.

It is a unique number to identify Dynamixel.

The range from 0 to 252 (0xFC) can be used, and, especially, 254(0xFE) is used as the Broadcast ID.
If the Broadcast ID is used to transmit Instruction Packet, we can command to all Dynamixels.

 

Please be cautious not to have the same IDs for the connected dynamixels. You may face communication issues or may not be able to search when IDs overlap.

It is the delay time per data value that takes from the transmission of Instruction Packet until the return of Status Packet.

0 to 254 (0xFE) can be used, and the delay time per data value is 2 usec.

That is to say, if the data value is 10, 20 usec is delayed. The initial value is 250 (0xFA) (i.e., 0.5 msec).

The angle limit allows the motion to be restrained.
The range and the unit of the value is the same as Goal Position(Address 30, 31).

• CW Angle Limit: the minimum value of Goal Position(Address 30, 31)
• CCW Angle Limit: the maximum value of Goal Position(Address 30, 31)

The following two modes can be set pursuant to the value of CW and CCW.

Operation Type	CW / CCW
Wheel Mode	both are 0
Joint Mode	neither at 0
Multi-turn Mode	both are 4095

The wheel mode can be used to wheel-type operation robots since motors of the robots spin infinitely.

The joint mode can be used to multi-joints robot since the robots can be controlled with specific angles.

Multi-turn mode allows joints have range of controllable position values from -28672 to 28672.

Adjusts position (zeroing). This value gets included in Present Position (36).

Present position + multi-turn offset.

Initial value is 0 and range is from -24576 to 24576

A Dynamixel with a position of 2048 with an applied offset of 1024 outputs a Present position of 3072.

  

It allows the user to change Dynamixel’s resolution.

The default Resolution Divider Value is set as 1. (1 ~ 4 available)

When resolution is lowered, revolutions (in both directions) can be increased (up to 28 turns in each direction).

Present Position = Real Position / Resolution Divider

For example, a Real Position of 2048 with a Resolution Divider set as 2 will yield a Present Position value of 1024 (2048/2 = 1024). A Dynamixel with Resolution Divider set as 2 will have a resolution 2048 for a single revolution.

The Present Position can be obtained while Multi-turn Offset and Resolution Divider are taken into account.

Present position = (Real Position / Resolution Divider) + Multi-turn Offset

For example, a Dynamixel with a Real Position of 2048 with a Resolution Divider set as 4 and Multi-turn Offset as 1024 will yield a Present Position of 1535 ((2048/4) + 1024 = 1535).

Caution : Do not set the temperature lower/higher than the default value. When the temperature alarm shutdown occurs, wait 20 minutes to cool the temperature before re-use. Using the product when the temperature is high may and can cause damage.

It is the operation range of voltage.

50 to 160 (0x32 ~ 0xA0) can be used.  The unit is 0.1V.

For example, if the value is 80, it is 8V.

If Present Voltage (Address42) is out of the range, Voltage Range Error Bit (Bit0) of Status Packet is returned as ‘1’ and Alarm is triggered as set in the addresses 17 and 18.

It is the torque value of maximum output. 0 to 1023 (0x3FF) can be used, and the unit is about 0.1%.

For example, Data 1023 (0x3FF) means that Dynamixel will use 100% of the maximum torque it can produce while Data 512 (0x200) means that Dynamixel will use 50% of the maximum torque. When the power is turned on, Torque Limit (Addresses 34 and 35) uses the value as the initial value.

It decides how to return Status Packet. There are three ways like the below table.

Value	Return of Status Packet
0	No return against all commands (Except PING Command)
1	Return only for the READ command
2	Return for all commands

 

When Instruction Packet is Broadcast ID, Status Packet is not returned regardless of Status Return Level.

DYNAMIXEL can protect itself by detecting errors occur during the operation. The errors can be set are as the table below.

Bit	Name	Contents
Bit 7	0	-
Bit 6	Instruction Error	When undefined Instruction is transmitted or the Action command is delivered without   the reg_write command
Bit 5	Overload Error	When the current load cannot be controlled with the set maximum torque
Bit 4	CheckSum Error	When the Checksum of the transmitted Instruction Packet is invalid
Bit 3	Range Error	When out-of-range value for target address is detected in the packet
Bit 2	Overheating Error	When the internal temperature is out of the range of operating temperature set in   the Control Table
Bit 1	Angle Limit Error	When Goal Position is written with the value that is not between CW Angle Limit and CCW   Angle Limit
Bit 0	Input Voltage Error	When the applied voltage is out of the range of operating voltage set in the Control Table

It is possible to make duplicate set since the function of each bit is run by  the logic of ‘OR’.

That is, if 0X05 (binary 00000101) is set, both Input Voltage Error and Overheating Error can be detected.

When Alarm LED occurs, the LED blinks and when Alarm Shutdown occurs, the motor output becomes 0 % by making the value of Torque Limit (Address 34, 35) as 0.

Value	Meaning
0	Keeps Torque from generating by interrupting the power of motor.
1	Generates Torque by impressing the power to the motor.

Bit	Meaning
0	Turn OFF the LED
1	Turn ON the LED

※ The relationship between Compliance Slop and PID Slope P Gain 8 128 16 64 32 32 64 16 128 8 The less the P gain, The larger the back lash, and the weaker the amount of output near goal position. At some extent, it is like a combined concept of margine and slope. It does not exactly match the previous concept of compliance. So it is obvious if you see the difference in terms of motion. ※ Explanation for PID required. For the brief explanation about general PID, please refer to the website(link) below. http://en.wikipedia.org/wiki/PID_controller FYI, PID control theory is not only limited to the control of motor(actuator) but is a generic theory that can be applied to all kinds of control.

It is the value of the maximum torque limit.  

0 to 1023 (0x3FF) is available, and the unit is about 0.1%.  

For example, if the value is 512, it is about 50%; that means only 50% of the maximum torque will be used.
If the power is turned on, the value of Max Torque is used as the initial value.

 

Notes: If the function of Alarm Shutdown is triggered, the motor loses its torque because the value becomes 0.  Once error conditions are resolved and this value is changed to the value other than 0, the motor can be operated again.

It means currently applied load.

The range of the value is 0~2047, and the unit is about 0.1%.

If the value is 0~1023, it means the load works to the CCW direction.

If the value is 1024~2047, it means the load works to the CW direction.

That is, the 10th bit becomes the direction bit to control the direction, and 1024 is equal to 0.

For example, the value is 512, it means the load is detected in the direction of CCW about 50% of the maximum torque.

 

 

Notes:Present load is an inferred value based on the internal output value; not a measured value using torque sensor, etc. Therefore, it may be inaccurate for measuring weight or torque. It is recommended to use it for predicting the direction and size of the force being applied to the joint.

It is the size of the current voltage supplied.

This value is 10 times larger than the actual voltage. For example, when 10V is supplied, the data value is 100 (0x64)

It is the internal temperature of Dynamixel in Celsius.

Data value is identical to the actual temperature in Celsius. For example, if the data value is 85 (0x55), the current internal temperature is 85℃.

Value	Meaning
0	There are no commands transmitted by REG_WRITE
1	There are commands transmitted by REG_WRITE.

 

Notes: If ACTION command is executed, the value is changed into 0.

Value	Meaning
0	Goal position command execution is completed.
1	Goal position command execution is in progress.

Value	Meaning
0	EEPROM area can be modified.
1	EEPROM area cannot be modified.

 

Caution: If Lock is set to 1, the power must be turned off and then turned on again to change into 0.

Value	Meaning
0	Turn off the torque mode. Executes Joint mode or Wheel mode.
1	Turn on the torque mode. Cannot control the position or moving speed but only Torque.

When Torque Control Mode Enable is at 1, DYNAMIXEL behaves like the followings
1. DYNAMIXEL does not control the position or the moving speed.
2. DYNAMIXEL controls with goal torque value.
3. DYNAMIXEL does not react to whatever value in Goal position and Goal speed.
4. Because position/moving speed is not controller, DYNAMIXEL behaves as if it is in the wheel mode.

These are the goal torque value

You can use 0 ~ 2047 (0x7FF), and the unit is 4.5mA.

(torque is directly proportional to the current value.)

If you use from 0~1023, torque is on toward CCW, and when you set it to 0, it stops.

If you use from 1024~2047, torque is on toward CW, and when you set it to 1024, it stops.

That means, 10^th bit becomes the direction bit, which controls direction.

Goal Torque cannot be bigger than Torque Limit(34,35)

This is Goal Acceleration value.

It can be used from 0~254(0XFE), and the unit is approximately 8.583 Degree / sec^2.

When it is set to 0, there is no control over acceleration and moves with the maximum acceleration of the motor.

When the goal speead is set to 0, there is no control over acceleration and moves with the maximum acceleration of the motor.

When it is set to 254, it becomes 2180 Degree / sec^2

For example, the current speed of Dynamixel is 0, and Goal acceleration is 10,

The speed of Dynamixel after 1 second will be 14.3 RPM.

The horn is installed on the front wheel gear serration of the DYNAMIXEL whereas the bearing set is installed on the back.

Installing the Front Horn

Place the thrust horn washer into the actuator before inserting the horn

You must carefully align the horn to the wheel gear serration by aligning dots.

Once alignment is properly done, gently push the center of the horn toward the actuator.

Make sure that the horn washer is in place as you tighten the bolt.

Installing the Bearing Set

You may need to remove the bearing set from the previous actuator and reinstall it into the new actuator.

The bearing set can also be purchased separately.

As bearing set is rotating freely, therefore alignment is not required when assembling to DYNAMIXEL.

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