Taie FY100, Руководство по связи

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4 MODBUS RTU Protocol
4 FY400/600/700/800/900 COMMUNICATION MANUAL
4 MODBUS RTU Protocol
4.1 Message Configuration
ID Number
1 Byte
Function Code
1 Byte
Data
N Byte
CRC
2 Byte
4.2 ID Number (Slave Address)
Range: 1~255.
Master instrument identifies slave controllers by the ID Number of the requested
message. ID Number should be configuring in individual slave controller by setting
parameter “IDNO” in operation LEVEL 3.
4.3 Function Code
Function Code Contents
03 (03H) Reading multiple registers value from slave controller
(Max register count : 8)
06 (06H) Setting 1 register value to slave controller
16 (10H) Setting multiple registers value to slave controller.
(Max register count : 8)
4.4 Data
Data depends on function code.
Request message from Master instrument is include “register address”, “data count”
and “setting data”.
Response data from Slave controller is include “byte count”, “data” and “abnormal
code”.
4.5 Error Check CRC
CRC16 generation polynomial:
1 2 15 16
X X X X
+ + +
CRC generation step is as below:
①
. CRC is initialized as FFFFH
②
. Calculate XOR with 1
st
data and the low byte of CRC. This is assumed as
Y(16bit).
③
. Shift Y one bit to the right. This assumed as Y.
④
. If a carry is generated at step 3, then calculate XOR with Y and “A001H”, else
jump to step 5.
⑤
. Repeat step 3 and 4, until Y is shifting right 8 times.
⑥
. Calculate XOR with next data and the low byte of Y. This is assumed as Y.
⑦
. Repeat step 3 ~5.