Xylem ODO RTU User Manual page 17

Request
Function Code
Register Address
Number Registers
Response
Function Code
Byte Count
Register Values
Error
Error Code
Exception Code
Modbus Configuration & Commands
1 byte
2 bytes
2 bytes
1 byte
1 byte
64 bytes
1 byte
1 bytes
0x04
0x0000
0x0020
0x04
0x40
ODO Saturation (%) [3:0]
ODO (mg/L) [3:0]
ODO Local Barometer Compensated (%) [3:0]
Temperature (C) [3:0]
Ref Temperature (C) [3:0]
Time Since Boot (ms) [3:0]
Conductivity (us/cm) [3:0]
Specific Conductivity (us/cm) [3:0]
Salinity (ppt) [3:0]
Conductivity nLF (us/cm) [3:0]
Total Dissolved Solids (mg/L) [3:0]
Reserved [3:0]
Reserved [3:0]
Reserved [3:0]
Reserved [3:0]
Reserved [3:0]
Reserved [3:0]
0x84
0x02 (Illegal Address)
17