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User’s Manual 2007-03-27
Closer to Real,
Dynamixel
RX-28
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DYNAMIXEL RX-28 Contents 1. Summary 1-1. Overview and Characteristics of RX-28 Page 2 1-2. Main Specifications Page 3 2. Dynamixel Operation 2-1. Mechanical Assembly Page 4 2-2. Connector Assembly Page 5 2-3. Dynamixel Wiring Page 6 3. Communication Protocol 3-1. Communication Overview Page 9 3-2. Instruction Packet Page 10 3-3. Status Packet Page 10 3-4. Control Table Page 12 4. Instruct
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DYNAMIXEL RX-28 1. Dynamixel RX-28 1-1. Overview and Characteristics of RX-28 Dynamixel RX-28 The Dynamixel series robot actuator is a smart, modular actuator that incorporates a gear reducer, a precision DC motor and a control circuitry with networking functionality, all in a single package. Despite its compact size, it can produce high torque and is made with high quality materials to provide the necessary strength and structural resilience to withstand large external forces. It a
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DYNAMIXEL RX-28 1-2. Main Specifications RX-28 Weight (g) 72 Gear Reduction Ratio 1/193 Input Voltage (V) at 12V at 16V Final Max Holding Torque(kgf.cm) 28.3 37.7 Sec/60degree 0.167 0.126 Resolution 0.3° Operating Angle 300°, Endless Turn Voltage 12V~16V (Recommended voltage: 14.4V) Max. Current 1200mA Operate Temperature -5℃℃ ~ +85 Command Signal Digital Packet Protocol Type RS485 Asynchronous Serial Communication (8bit,1stop,No Parity) Link (Physical) RS485 Multi Dr
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DYNAMIXEL RX-28 2. Dynamixel Operation 2-1. Mechanical Assembly Option Frames OF-28B OF-28S RXOF-28H Horn-28T 4
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DYNAMIXEL RX-28 Assembly Sample assembly using option frames. 2-2 . Connector Assembly Assemble the connectors as shown below. Attach the wires to the terminals using the correct crimping tool. If you do not have access to a crimping tool, solder the terminals to the wires to ensure that they do not become loose during operation. 5
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DYNAMIXEL RX-28 2-3. Dynamixel Wiring Pin Assignment The connector pin assignments are as the following. The two connectors on the Dynamixel are connected pin to pin, thus the RX-28 can be operated with only one connector attached. ( Note : The pin number of connector’s edge cut side is PIN1) PIN1: GND PIN4: D- PIN2: VDD(12V~21V) PIN3: D+ PIN3: D+ PIN2: VDD(12V~21V) PIN4: D- PIN1: GND Wiring Connect the RX-28 actuators pin to pin as shown below. Many RX-28 ac
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DYNAMIXEL RX-28 Connection to UART To control the Dynamixel actuators, the main controller needs to convert its UART signals to the RS485 type. The recommended circuit diagram for this is shown below.\ CCW VDD VDD The power is supplied to the Dynamixel actuator from the main controller through Pin 1 and Pin 2 of the Molex3P connector. (The circuit shown above is presented only to explain the use of RS485 UART. The CM-2 PLUS controller already has the abo
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DYNAMIXEL RX-28 Caution Please ensure that the pin assignments are correct when connecting the Dynamixel actuators. Check the current consumption when powering on. The current consumption of a single Dynamixel actuator unit in standby mode should be no larger than 50mA Connection Status Verification When power is applied to the Dynamixel actuator, the LED blinks twice to confirm its connection. Inspection If the above operation was not successful, then check the co
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DYNAMIXEL RX-28 3. Communication Protocol 3-1. Communication Overview Packet The main controller communicates with the Dynamixel units by sending and receiving data packets. There are two types of packets; the “Instruction Packet” (sent from the main controller to the Dynamixel actuators) and the “Status Packet” (sent from the Dynamixel actuators to the main controller.) Instruction Packet Main Controller Status Packet Communication For the system connection below,
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DYNAMIXEL RX-28 3-2. Instruction Packet The Instruction Packet is the packet sent by the main controller to the Dynamixel units to send commands. The structure of the Instruction Packet is as the following. Instruction Packet OXFF 0XFF ID LENGTH INSTRUCTION PARAMETER1 …PARAMETER N CHECK SUM The meanings of each packet byte definition are as the following. 0XFF 0XFF The two 0XFF bytes indicate the start of an incoming packet. ID The unique ID of a Dynamixel unit. There are 254
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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 - Set to 1 if an undefi
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DYNAMIXEL RX-28 3-4. Control Address Item Access Initial Value 0(0X00) Model Number(L) RD Table 28(0x1C) 1(0X01) Model Number(H) RD 0(0x00) 2(0X02) Version of Firmware RD ? 3(0X03) ID RD,W R 1(0x01) 4(0X04) Baud Rate RD,W R 34(0x22) 5(0X05) Return Delay Time RD,W R 250(0xFA) 6(0X06) CW Angle Limit(L) RD,W R 0(0x00) 7(0X07) CW Angle Limit(H) RD,W R 0(0x00) 8(0X08) CCW Angle Limit(L) RD,W R 255(0xFF) 9(0X09) CCW Angle Limit(H) RD,W R 3(0x03) 10(0x0A) (Reserved) - 0(0x00) 11(0X0B)
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DYNAMIXEL RX-28 Control Table The Control Table contains information on the status and operation of the Dynamixel actuator. The Dynamixel actuator is operated by writing values to its control table and its status is checked by reading values off its control table. RAM and EEPROM The data values for the RAM area will be set to the default initial values whenever the power is turned on. However, the data values for the EEPROM area are non-volatile and will still remain even after the pow
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DYNAMIXEL RX-28 Address 0x05 Return Delay Time. The time it takes for the Status Packet to return after the Instruction Packet is sent. The delay time is given by 2uSec * Address5 value. Address 0x06,0x07,0x08,0x09 Operating Angle Limit. Sets the Dynamixel actuator’s operating angle range. The Goal Position needs to be within the range of: CW Angle Limit <= Goal Position <= CCW Angle Limit. An Angle Limit Error will occur if the Goal Position is set outside this range set by the oper
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DYNAMIXEL RX-28 In the case of an instruction which uses the Broadcast ID (0XFE) the Status Packet will not be returned regardless of the Address 0x10 value. Address 0X11 Alarm LED. If the corresponding Bit is set to 1, the LED blinks when an Error occurs. Bit Function Bit 7 0 Bit 6 If set to 1, the LED blinks when an Instruction Error occurs Bit 5 If set to 1, the LED blinks when an Overload Error occurs Bit 4 If set to 1, the LED blinks when a Checksum Error occurs Bit 3 If se
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DYNAMIXEL RX-28 Address 0x18 Torque Enable. When the power is first turned on, the Dynamixel actuator enters the Torque Free Run condition (zero torque). Setting the value in Address 0x18 to 1 enables the torque. Address 0x19 LED. The LED turns on when set to 1 and turns off if set to 0. Address 0x1A~0x1D Compliance Margin and Slope. The compliance of the Dynamixel actuator is defined by setting the compliance Margin and Slope. This feature can be utilized for absorbing shocks at t
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DYNAMIXEL RX-28 Address 0x20,0x21 Moving Speed. Sets the angular velocity of the output moving to the Goal Position. Setting this value to its maximum value of 0x3ff moves the output with the maximum angular velocity which depends on the level of power supplied and Dynamixel series. (The lowest velocity is when this value is set to 1. When set to 0, the velocity is the largest possible for the supplied voltage, e.g. no velocity control is applied.) Address 0x24,0x25 Present Position.
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DYNAMIXEL RX-28 Goal Speed Setting BIT 15~11 10 98 765 43 21 0 Value 0 Turn Direction Speed Value Turn Direction = 0 : CCW Direction Turn, Load Direction = 1: CW Direction Turn Range Each data has a valid minimum and maximum values. Write instructions made outside of these valid ranges will return an error. The following table summarizes the data range for each register. 16 bit data registers are indicated with two bytes (L) and (H). Both bytes need to be written at the same tim
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DYNAMIXEL RX-28 4. Instruction Set and Examples The following Instructions are available. Number of Instruction Function Value Parameter PING No action. Used for obtaining a Status Packet 0x01 0 READ DATA Reading values in the Control Table 0x02 2 W RITE DATA W riting values to the Control Table 0x03 2 ~ Similar to W RITE_DATA, but stays in standby REG W RITE 0x04 2 ~ mode until the ACION instruction is given Triggers the action registered by the ACTION 0x05 0 REG_W
