Agrowtek SXC Climate Sensor
Canopy climate sensor for temperature, humidity, PPFD light, CO2 and leaf temperature.
The Agrowtek SXC is an aspirated climate sensor that hangs above the crop canopy in greenhouses and grow rooms and measures air temperature, humidity, PPFD light and, as options, CO2 and leaf temperature. This Modbus RTU template reads all sensor values and identification through the LX2 ModLINK, and lets you write calibration offsets, the units toggle and the humidity sensor heater from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 29, read and write
- Brand
- Agrowtek
- Key readings
- Air temperature · Relative humidity · PPFD light level · CO2 concentration · Leaf temperature
- Available commands
- Calibration offsets · Temperature units · Humidity sensor heater · Modbus address
- Compatible models
- SXC
- Last updated
Registers (29)
17 read, 13 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Temperature | °C | Read | |||
| Relative Humidity | %RH | Read | |||
| Light | µmol/m²/s | Read | |||
| CO2 | ppm | Read | |||
| Leaf Temperature | °C | Read | |||
| Sensor Value 6 | Read | ||||
| Temperature Float | °C | Read | |||
| Relative Humidity Float | %RH | Read | |||
| Light Float | µmol/m²/s | Read | |||
| CO2 Float | ppm | Read | |||
| Leaf Temperature Float | °C | Read | |||
| Toggle Units | Write | ||||
| Humidity Sensor Heater | Write | ||||
| Temperature Offset Calibration | °C | Write | |||
| Humidity Offset Calibration | %RH | Write | |||
| Light Offset Calibration | µmol/m²/s | Write | |||
| CO2 Offset Calibration | ppm | Write | |||
| Leaf Temperature Offset Calibration | °C | Write | |||
| Temperature Analog Output Calibration | Write | ||||
| Humidity Analog Output Calibration | Write | ||||
| Light Analog Output Calibration | Write | ||||
| CO2 Analog Output Calibration | 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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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show canopy temperature, humidity, light and CO2 for each greenhouse section on one ModbusCloud dashboard.
- Get an email or webhook when CO2 falls below your enrichment target or rises above a safety limit.
- Compare leaf and air temperature over 365 days of history to judge screens, heating and lighting.
- Detect light leaks during the dark period with an alarm rule on the PPFD value.
- Catch a failed temperature or humidity element with a rule on the value 9999, which the sensor reports when it fails.
- Correct a drifting reading with an offset written from ModbusCloud after checking it against a reference.
Installation
Hang the SXC above the crop canopy and connect its GrowNET port with a standard RJ45 cable to an Agrowtek LX2 ModLINK, directly or through an HX8 hub.
Wire TX/RX+ and TX/RX- of the LX2 to the RS485 terminals of the ModbusCloud Gateway and terminate the bus at both ends. Power the LX2 with 24 Vdc, which the SXC needs for its fan and optional sensors.
Give the sensor its own address from 1 to 247 with the AgrowLINK utility and an LX1 USB AgrowLINK, or write it to the address register at broadcast address 254 while it is the only device on the bus.
In ModbusCloud, add a Modbus device with protocol RTU, the sensor address, 19200 baud, 8 data bits, no parity and 1 stop bit, and import this template.
Check that temperature and humidity show plausible values. If your SXC has no CO2 or PLIR option, remove those registers from the Modbus device.
Things to watch for
The sensor does not answer through the LX2. What should I check?
Check 19200 baud, no parity, 1 stop bit and the sensor address in ModbusCloud; the LX2 may have been set to another speed with the ModLINK utility. Swap TX/RX+ and TX/RX- if nothing comes back, terminate the RS485 bus, and make sure every GrowNET device behind the LX2 has its own address.
The temperature looks far too high. Is it in Fahrenheit?
Probably. The sensor units can be toggled between °C and °F, and the template labels the value °C. Writing 1 to Toggle Units switches the temperature back. A value of 9999 means a failed sensor; a failed CO2 sensor reads 0.
Why do I see every value twice?
The SXC gives each value as a scaled whole number and as a floating-point value with the same reading. Keep the one you want on your dashboards and remove the other from the Modbus device if you do not need it.
Can I calibrate the sensor from ModbusCloud?
Yes. Write the correct value to the offset register of that sensor, for example 25.00 °C for temperature, and the sensor corrects itself. CO2 only accepts 400 ppm in fresh outdoor air. Writing 1 to Clear Calibration restores the factory calibration. Writing is off per gateway by default; request it for the gateway in the portal.
Can I plug the GrowNET cable into the network port of the Gateway?
No. GrowNET uses RJ45 plugs but it is not Ethernet. Connect the sensor to the LX2 ModLINK and wire the LX2 to the RS485 terminals of the ModbusCloud Gateway.
Want to see how it works?
