CHAPTER 13 RS-485 COMMUNICATIONS
Modbus RTU Communications 13-15
13
<Response message example>
Station No. 1byte 01
FC
1byte 17
No. of data bytes 1byte 0C
00 ・・・ Feedback speed: 1000 [r/min] (3E8h)
00
03
Data 1 4byte
E8
00 ・・・ Effective torque: 80 [%] (50h)
00
00
Data 2 4byte
50
00 ・・・ Motor current: 80 [%] (50h)
00
00
Information
Data 3 4byte
50
19
CRC check
16 bits
(2 bytes)
5F
FC 08h (Echo back maintenance )
(1) Query from the master
Station No. 1 byte
FC 1 byte
・・・
08h
(H)
Sub code
2 bytes
(L)
・・・
Specify 0000h as the sub code of echo back.
(H)
Information
Data
2 bytes
(L)
・・・
Specify an arbitrary data.
(L)
CRC check
16 bits
(2 bytes)
(H)
(2) Response message from the amplifier
Station No. 1 byte
FC 1 byte
・・・
08h
(H)
Sub code
2 bytes
(L)
・・・
0000h
(H)
Information
Data
2 bytes
(L)
・・・
Echo back the specified data.
(L)
CRC check
16 bits
(2 bytes)
(H)