BOQU BH-485-NH, User Manual, Page: 34 / 42

Operating Manual of Ammonia Nitrogen Sensor
31
Chapter 7 Communication Protocol
A. The sensor probe has Modbus RS485 function, communicates in RTU mode, and the default baud rate
is 9600. It can communicate with the host computer (PC/digital instrument, etc.) with RS485
communication function. The specific MODBUS-RTU table is shown in the table below.
MODBUS-RTU
Baud rate 9600/4800/19200/38400/115200
Data bit 8 digits
Parity no
Stop bit 1 digit
Slave address 1-254 (default 10)
B
、
Adopt MODBUS standard communication protocol. The specific agreement content is shown in the
table below.
Address Name
Data
Type Operate
Type
Remarks
0 Temp. Value float read 03 command
2
pH Value
float read 03 command
16 Ammonia Nitrogen float read 03 command
18
Potassium ion value
float read 03 command
35
Equipment serial number SN1
unsigned read 03 command
36
Equipment serial number SN2
unsigned read 03 command
37 Equipment serial number SN3 unsigned read 03 command
70
Year
float read/write 03 command /16 command
72
Month
float read/write 03 command /16 command
74
Day
float read/write 03 command /16 command
76 Hour float read/write 03 command /16 command
78
Minute
float read/write 03 command /16 command
80
Second
float read/write 03 command /16 command