User’s Manual Ver.1.0 RS301CR/RS302CD Command Type Servo for Robot Instruction Manual Caution Read this instruction manual before use. Keep this manual handy for immediate reference.
CONTENTS １．FOR SAFETY ● ● ● ● WARNING SYMBOLS ............................................................................................. CAUTIONS FOR USE ............................................................................................. WARNINGS IN HANDLING BATTERIES ............................................................. Cautions for Storage ................................................................................................. 4 4 5 5 ２．INTRODUCTION ● Features ............
No.26 /No.27 Compliance Slope .................................................... 21 No.28 /No.29 Punch ....................................................................... 21 ● Variable RAM Area ................................................................................................. 23 No.30 /No.31 Goal Position ............................................................ No.32 /No.33 Goal Time ................................................................. No.35 Maximum Torque .............
1.FOR SAFETY To use this product safely, please pay your full attention to the followings. Be sure to read this instruction manual prior to using this product. Warning Symbols The warning symbols used in this text are defined as follows: Meaning Indication Danger Indicates a hazard that will cause severe personal injury, death, or substantial property damage if the warning is ignored.
Do not turn the servo horn forcibly. Otherwise, the servo will be damaged. Do not leave the servo locked. If the servo continues to be locked due to a strong external force, it may cause smoke, fire or damage. Warnings in Handling Batteries Warning Do not use any battery charger other than the specified charger. Otherwise, the battery may be get damaged, fire, smoke or liquid leakage. Be sure to use batteries recommended by Futaba. Do not use battery packs connected in parallel.
2.INTRODUCTION Features RS301CR/RS302CD servo is especially designed for robotic applications, having the following features. trembling its arms and legs and to absorb turbulence from external force. ● Calibration ● Small and Lightweight RS301CR and RS302CD are small and lightweight servos specially designed for robots, which are 28g and 21g respectively. Angular position of every RS301CR/RS302CD servo is calibrated by our standard gauge before their shipment.
Part Names / Handling Instructions Screws for fixing the servo to a case ※ Do not remove these screws. Output-axis Connecter Caution Fig.2.1 Part names Removing the screws for fixing the servo with a case may damage the servo.
3.CONNECTION System Configuration The following figure shows a robotic system using RS301CR/RS302CD servos, RPU-10 processor unit and etc. Motion editor Control softwar RS301CR RS302CD Processing Unit (RPU-10 etc.） RSC-U485 Battery (PR-4S780P) Fig. 3.1 Robotic system configuration Pin Assignment Pin assignment of the RS301CR/RS302CD servo is shown below. ②④ ①③ ① ② ③ ④ Gray Black Gray Black ：RS485(D-) ：RS485(D+) ：VCC(7.4V) ：GND Fig. 3.
Cautions when Connecting Please refer to the figure below for connecting RS301CR/RS302CD and RPU-10. PC Please prepare it by your self RPU-10 RS232C PR-4S780P Relay box RS301CR/RS302CD Fig. 3.3 Operating with RPU-100 Allowable current for relay connectors is 2A and for servo harness is 3A each for continues use. Set your PC’s communication parameters as follows; Baud rate ：115.2 bps （adjustable between 9.6kbps and 460kbps, Refer to Table 4.6 Baud rate in p.
4.CONTROL METHOD Abstract ● Communication Protocol The communication protocol of the RS301CR/RS302CD servo is based on RS485 (IEEE485) half duplex communication. Data transmission and reception are carried out alternatively on the same signal line. Normally, the RS301CR/RS302CD servo stands by in reception mode. But, when it receives from RPU-10 a command to send the servo’s data and status, it switches to transmission mode, sends them out and finally returns to reception mode.
Packet Format ●Short Packet Short packets are used for sending the data in the memory map toward a single servo. Packet structure Header ID Flags Address Length Count Data Header Sum This is a line head of a packet. FAAFH is used for short packets. “xH” denotes Hexadecimal number. ID This is a servo’s ID. The valid numbers are from 1 through 127 (00H ~ 7FH). When ID is set to 255, commands are commonly effective to all servos. The processor unit cannot obtain any data from servos at this time.
Ex）Write the data of the ID1 servo into the Flash ROM. Hdr ID Flg Adr Len Cnt Sum FA AF 01 40 FF 00 00 BE The servo’s memory should be renewed with the data you want to write into the Flash ROM by transferring the data by using a short packet beforehand. The servo ID becomes effective only after receiving a packet. The ID returns to the previous number on the next boot up unless the ID is written into the Flash ROM. Caution Never turn off the power while the Flash ROM is being written.
Bit3 ~ Bit0：Address assignment of a return packet (1) Data return from predetermined addresses Setting the Bit3 through Bit0 like the table below when sending a short packet makes it possible to receive the data of the specified addresses in the servo’s memory map. The Bit0 indicates whether to require a return packet (Bit0=1) or not (Bit0=0). Please refer to the Table 4.1 Send packet flags (p.11) for setting these bits in sending short packets.
Address This notation indicates an address on the memory map. Using this address makes it possible to write the data of the specified number of bytes determined by the “Length” into the memory map. This notation indicates the length of a data block. Length Length = the number of bytes of data Count This notation indicates the number of servos, which should be set at “1” for a short packet. Data This notation indicates the data to be stored in the memory map.
Address This indicates an address on the memory map. Using this address makes it possible to write the data of the specified number of bytes determined by the “Length” into the memory maps of multiple servos. Length This is used to specify the number of bytes of the data for a servo. Length = the number of bytes of data + 1 Count This notation indicates the number of servos that data is sent to. VID and data are sent to all of them. VID This field represents the ID of each servo which sends data.
●Return Packet A return packet is the packet returned from the servo when the Flag field requests a servo to send a return packet. Packet structure Header ID Flags Address Length Count Data Header Sum This field denotes the beginning of the packet. For a short packet, the header is FDDFH. ID This field represents the servo ID. Flags This field represents the flags which are set in the packet. Each bit shown in the table below represents a servo state. Table 4.
Memory Map ●Invariable ROM area Table 4.4 Invariable ROM area Area Adress No. Initial Name Property 10H(20H) Model Number L R 01H 30H Model Number H R 02 02H 01H Firmware Version R 03 03H 00H Reserved - DEC HEX value 00 00H Invariable 01 ROM ( ) For RS302CD ●No.0 / No.1 Model Number(2Bytes, Hex Number, Read Only) This field represents the model No. (servo model). For the RS301CR, it is: Model Number L = 10H Model Number H = 30H For RS302CD, they are as follows.
●Variable ROM area Table 4.5 Variable ROM area Area ROM Adress No.
●No.4 Servo ID(1Byte, Hex Number, Read/Write) This data represents the servo ID. Its initial value is 01H. The setting range is 1 ~ 127 (01H ~ 7FH). Ex) Rewrite servo ID1 to ID5. Hdr ID Flg Adr Len Cnt Dat Sum FA AF 01 00 04 01 01 00 05 The relevant servo begins to operate under the new ID as soon as the ID rewrite command is received. Note that after the ID was rewritten, if it was not written to the flash ROM, when the power is turned off, it will return to the previous ID. ●No.
●No.7 Return Delay（１ Byte,Hex Number,Read/Write） This indicates the delay time for reply when the return packet is required. The servo sends the return packet in 100μs after receiving data with the setting of 0. The parameters of No.7 are in units of 001H = 50μs. If you want to set the delay time for reply to 1ms, write 18 (12H). （1ms=100μs+18x50μs） Hdr ID Flg Adr Len Cnt Dat Sum FA AF 01 60 07 01 01 12 74 ●No.8~No.
*Note that rewriting this memory map value will null and void the product warranty. ●No.24 / No.25 Compliance Margin(1Byte, Hex Number, Read/Write) These data specify the allowable range of the servo stop position. If the present value is within the range set here relative to the specified target position, the servo is judged to have reached the target position and is stopped. CW and CCW can be set individually. Setting is in approximately 0.1 Degree units. The initial value is 02H(0.2 degree).
84 03 CCW Target position Punch Punch CCW CW A B C D CW A： B： C： D： CCW Compliance Slope CCW Compliance Margin CW Compliance Margin CW Compliance Slope Fig. 4.1 Compliance control Ex. 1) Set punch to 0064H(1%). Hdr ID Flg Adr Len Cnt FA AF 01 00 1c 02 01 Dat Sum 64 00 7A Ex.
●Variable RAM Area Table 4.7 Variable RAM area Area RAM Adress No.
●No.30 / No.31 Goal Position(2Bytes, Hex Number, Read/Write) A servo can be moved to the specified angle. The center of the movement range is 0 degree. Viewed from the top of the servo (nameplate side), the CW (clockwise rotation) direction is “+” and the CCW (counterclockwise rotation) direction is “－“. When the “No.5 Servo Reverse” is 01H, CW direction is “-” and the CCW direction is “+”. The goal position unit is about 0.1 deg. To make 90 degrees the target position, set “900” (900→384H).
The setting range is between 0H and 64H. Ex) Set the maximum torque of servo ID=1 to 80% (50H). Hdr ID Flg Adr Len Cnt Dat Sum FA AF 01 00 23 01 01 50 72 ●No.36 Torque Enable(1Byte, Hex Number, Read/Write) The servo torque can be enabled and disabled. 01H enables the torque and 00H disables the torque. When the power is turned on, the torque is disabled (00H). When 02H is set, the servo enters the brake mode and the servo horn can be freely rotated by hand, but a weak torque is generated.
If you send only flags, set [COUNT] =1 with [ADRESS]=0 and [LENGTH]=0, and nothing should be written in「Data」. Hdr ID Flg Adr Len Cnt Dat Sum FA AF 01 09 24 01 01 01 2D Return Packet Hdr ID Flg Adr Len Cnt FD DF 01 00 2A 12 01 Sum 84 03 00 00 00 00 06 00 BA 03 00 00 00 00 00 00 00 00 00 Memory Map No. 42 43 4 4 45 46 47 4 8 49 50 51 5 2 53 54 55 5 6 57 58 59 As the 2 bytes from the beginning of the return packet data are memory map address Nos. 42 and 43, the present position is 0384H(90.
● No.46/No.47 Present Speed（２ Byte,Hex Number,Read） You can get the servo’s current rotation speed on deg/sec basis. Ex.）To read the current rotation speed of the servo in ID=1 If you want to get the values of No.46 and No.47 in the servo’s memory map as return packets, send the packets with the bits of 1 to 3 in the “Flag” set to bit3=1、bit2=0、bit1=0 and bit0=1. After sending, the values for the items between No.42 and No.59 in the memory map will be sent back to you from the servo.
Ex.) To send flags for the return packets between No.42 and No.59 in the memory map. Hdr ID Flg Adr Len Cnt Sum FA AF 01 09 00 00 01 09 Return Packet Hdr ID Flg Adr Len Cnt Dat FD DF 01 00 2A 12 01 Sum 4E FB 00 00 00 00 06 00 BA 03 00 00 00 00 00 00 00 00 32 Memory Map No. 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 The present load is 0006H, which is identified by the values of No.48 andNo.
Return Packets Hdr ID Flg Adr Len Cnt Dat FD DF 01 00 2A 12 01 Sum 4E FB 00 00 00 00 06 00 2D 00 00 00 00 00 00 00 00 00 A6 Memory Map No. 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 The current temperature is 002DH(45℃), which is identified by the values of No.50 and No.51 in the return packet. ● No.52/No.53 Present Voltage （２ Byte,Hex Number,Read） This shows the voltage that is currently used for the servo.
5. REFERENCE Specifications APPLICATION FEATURES OTHERS ROBOT ACTUAT0R RS485 SERIAL COMMINUCATION MOTOR CONTROL by SOFTWARE SIZE（L×W×H）： RS301CR RS302CD 35.8 × 19.6 × 25.0 [mm] 35.8 × 19.6 × 25.0 [mm] WEIGHT RS301CR RS302CD 28 21 ： Operation Current ：IN SUSPENSION RS301CR （ROOM TEMPERATURE, No Load, 7.4V） RS302CD [g] [g] 40±20 [mA] 40±20 [mA] ：IN WORKING RS301CR 110±40 [mA] （ROOM TEMPERATURE, No Load, 7.4V） RS302CD 100±40 [mA] MAXIMUM OUTPUT TORQUE: (7.4V) RS301CR RS302CD 7.1 5.
DIMENSIONS Figure 0-1 Dimensions with using Joint-Ball 31
TROUBLESHOOTING If your servo does not operate, it intermittently stops operating, or it operates erroneously, take the action shown in the table below. If this does not correct the trouble, please contact a Futaba dealer. Table 0-1 Check list Check point Check item Battery Dead battery. Action Replace the battery. Incorrect loading voltage. Charge the LiPo battery. Reload the batteries in the correct polarity. Change the recommanded battery Connecter Faulty contact connection.
