FUTABA RS204MD, Instruction Manual

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Bit 3～0 : Direct Address of Return Packet
(1)Direct Area of Memory Map
Setting Bit 3 to Bit 0 of a Short Packet as Table 4.3 , you can receive return data of the specified area of
servo’s memory map.
The RS485 half-duplex communication does not allow addressing more than one servo that can send a
return packet. After requesting a return packet, do not send next data until completing receiving of the
return packet.
Table 4.3 Direct Area of memory map
Bit 3 2 1 0 Function
0 0 0 0 No return Packet
0 0 0 1 Return ACK/NACK Packet
0 0 1 1 Return the data of memory map No.00～No.29
0 1 0 1 Return the data of memory map No.30～No.59
0 1 1 1 Return the data of memory map No.20～No.29
1 0 0 1 Return the data of memory map No.42～No.59
1 0 1 1 Return the data of memory map No.30～No.41
1 1 1 1 Return the specified number of bytes of data starting from
the specified address
(2)Direct specified address
Setting the Bit 3 to Bit 0 to “1” and sending a short command with the starting address whose data you
want to receive, the length of data and the count=00H makes it possible to return the specified number
of bytes of the data starting from the specified address.
Available addresses in the memory map are from No.00 to No.139 (00H~8BH).
Ex)Return the data of addresses from No.42 (2AH) through No.43 (2BH) of the servo(ID:1).
Hdr ID Flg Adr Len Cnt Sum
FA AF 01 0F 2A 02 00 26
(3)ACK/NACK Packet
By sending a Short Packet with the Bit 0=1, Bit1=0, Bit2=0, Bit3=0, the servo will return ACK/NACK
packet.
ACK/NACK Packet is only 1 byte of data that is
07H = “ ACK ” or 08H = “ NACK ” .