Agrowtek SXO2 Dissolved Oxygen Sensor
Optical dissolved oxygen transmitter for nutrient tanks and hydroponics: oxygen and water temperature.
The Agrowtek SXO2 is an optical dissolved oxygen transmitter with display that measures oxygen and water temperature in nutrient tanks, hydroponic systems and process water. This Modbus RTU template reads dissolved oxygen, water temperature and identification, and lets you write zero and span calibration and the device address from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 16, read and write
- Brand
- Agrowtek
- Key readings
- Dissolved oxygen · Water temperature · Serial number
- Available commands
- Zero calibration · Span calibration · Units toggle · Device address
- Compatible models
- SXO2 · Agrowtek SXO2 dissolved oxygen transmitter and data logger with ODO probe
- Last updated
Registers (16)
10 read, 7 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Dissolved Oxygen | mg/l | Read | |||
| Water Temperature | °C | Read | |||
| Dissolved Oxygen Float | mg/l | Read | |||
| Water Temperature Float | °C | Read | |||
| Toggle Units | Write | ||||
| Temperature Zero Calibration | °C | Write | |||
| DO Zero Calibration | mg/l | Write | |||
| Temperature Span Calibration | °C | Write | |||
| DO Span Calibration | mg/l | Write | |||
| Clear Calibration | Write | ||||
| Device Address | Read and write | ||||
| Serial Number | Read | ||||
| Date of Manufacture | Read | ||||
| Hardware Version | Read | ||||
| Firmware Version | Read | ||||
| Device Model | Read |
Loading registers…
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Use cases
- Send an alert when dissolved oxygen in a nutrient tank drops below your limit.
- Show oxygen and water temperature of every tank on one dashboard.
- Compare oxygen levels with water temperature over 365 days of history.
- Check after maintenance that the oxygen reading has returned to its usual range.
- Start an aeration pump from an automation when oxygen falls too low.
Installation
Install the ODO probe in the tank or pipe and connect the SXO2 GrowNET RJ45 port to an Agrowtek LX2 ModLINK.
Wire TX/RX+ and TX/RX- of the LX2 to RS485 A and B of the ModbusCloud Gateway, with termination at the bus ends.
Give the SXO2 a unique address in the SETUP menu and leave the LX2 at 19200 baud, 8 data bits, no parity, 1 stop bit.
In ModbusCloud, add a Modbus RTU device with that address and import this template.
Check that oxygen and temperature match the display of the transmitter.
Things to watch for
The transmitter shows values but does not answer on Modbus.
The SXO2 speaks Modbus only through an LX2 ModLINK. Check the RJ45 cable, the LX2 power, the A and B wiring and that the address is unique on the bus.
The oxygen reading drifts or looks too low.
Check that the probe is wet and clean and that the sensor cap is not worn. Calibrate the zero point first, then span with water saturated air, as described for the probe. A new sensor cap needs its coefficients loaded.
How do I calibrate from ModbusCloud?
Write the correct value x100 to the zero register first, then to the span register; the transmitter calibrates at once. Writing 1 to Clear Calibration restores the factory calibration. Only calibrate with the probe in a known reference.
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