Bio Instruments FI-xT-485M
Phyto-Sensor fruit growth sensor that measures fruit diameter in millimetres over RS485.
The Bio Instruments FI-xT-485M is a Phyto-Sensor fruit growth sensor that clamps onto a single fruit and measures its diameter to follow growth and temporary shrinkage on the plant. This Modbus RTU template reads the fruit diameter and the communication settings, and lets you change the address, baud rate and parity from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 9600 baud
- Registers
- 5, read and write
- Brand
- Bio Instruments
- Key readings
- Fruit diameter · Modbus address · Baud rate · Parity
- Available commands
- Modbus address · Baud rate · Parity
- Compatible models
- FI-ST-485M · FI-MT-485M · FI-LT-485M
- Last updated
Registers (5)
5 read, 3 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Fruit Diameter | mm | Read | |||
| Fruit Diameter Float | mm | Read | |||
| Device Address | Read and write | ||||
| Baud Rate Code | Read and write | ||||
| Parity Code | Read and write |
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 the diameter of sample fruits on a greenhouse dashboard and follow their growth per day and per week.
- Compare daytime shrinkage and night-time recovery of the fruit with irrigation times to judge the water supply.
- Keep 365 days of diameter history to compare growth between plantings, varieties or greenhouse sections.
- Get an email or webhook when the diameter drops below a threshold you set, for example when the sensor has slipped off the fruit.
- Give each sensor its own address from ModbusCloud before you add more sensors to the same RS485 line.
Installation
Open the clamping jaws, place the fruit between them in the desired position and check that the sensor holds it firmly. Secure the cable to the stem or a support.
Connect black to ground, yellow to RS485 B and white to RS485 A of the ModbusCloud Gateway, and red to a 5 to 24 Vdc supply. Terminate both ends of the bus with 120 Ω.
Give every sensor on the bus its own address with the Bio Instruments address tool or by writing Device Address. All sensors leave the factory with address 247.
In ModbusCloud, add a Modbus device with protocol RTU, the sensor address, 9600 baud and 8E1, and import this template.
Check that Fruit Diameter matches the size of the fruit and lies within the range of your model.
Things to watch for
The sensor does not answer. What should I check?
Check 9600 baud, even parity, 1 stop bit and address 247 in ModbusCloud; many tools default to no parity. Swap A and B if nothing comes back, connect the black ground wire to the bus ground, and terminate both ends of the bus, because the sensor has no termination resistor inside.
The diameter jumps or stays at the end of the range. What is wrong?
Check that the fruit sits firmly between the jaws and that the cable is fixed to the stem, so wind or plant handling cannot move the sensor. A value at the lower or upper end means the fruit is outside the model range: use FI-S for 7 to 45 mm, FI-M for 15 to 90 mm and FI-L for 30 to 160 mm.
Why do I see every measured value twice?
The sensor gives each measurement as a scaled whole number and as a floating-point value. Both carry the same reading. Keep the one you want on your dashboards and remove the other from the Modbus device in ModbusCloud if you do not need it.
Can I change the address, baud rate or parity from ModbusCloud?
Yes, these three registers are writable. Writing is off per gateway by default; request it for the gateway in the portal. After a new address the sensor only answers on that address. Change baud rate or parity only when every device on the bus gets the same setting, and update the Modbus device in ModbusCloud right away.
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