Fuji Electric ALPHA7, User Manual

Page: 553 / 662

CHAPTER 13 MODBUS RTU COMMUNICATION
13-14
Transmission Protocol
13
(3) Message examples
Shows a message example to write in three pieces of coil data from CONT22 signal.
<Query example>
Station No. 1 byte 01 ･･･
When the amplifier station no. is "1".
FC 1 byte 0F ･･･
0Fh
Information
Address 2 bytes
02
･･･
Specify 0215h as the CONT22 signal address.
15
No. of coil data 2 bytes
00
･･･
Specify 3 = 0003h as the number of coils.
03
No. of data bytes
1 byte 01
･･･
The value obtained from 3 pcs/8 and by rounding
up decimal
Data 1 1 byte 06
･･･
See below.
CRC check
16 bits
(2 bytes)
03
74
Data are allocated from LSB in order starting from the smaller address.
The corresponding bit indicates ON with "1" and OFF with "0". The rest of bits are all fixed to "0."
Data1 (=06h)
0 0 0 0 0
CONT24
1 (ON)
CONT23
1 (ON)
CONT22
0 (OFF)
<Response message example>
Station No. 1 byte 01
FC 1 byte
0F
Information
Address 2 bytes
02
15
No. of coil data 2 bytes
00
03
CRC check
16 bits
(2 bytes)
05
B6