Agrowtek VXi Irrigation Valve Controller
Irrigation valve controller with eight 24 V outputs and four analog inputs on the VX12i.
The Agrowtek VXi is an irrigation valve controller that drives eight 24 V AC or DC valves for watering zones in greenhouses and indoor farms, and on the VX12i also reads four analog sensors. This Modbus RTU template reads the state and closure count of each output and the analog inputs through the LX2 ModLINK, and lets you open and close valves and set the communication timeout from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 31, read and write
- Brand
- Agrowtek
- Key readings
- Valve output states · Closure count per output · Analog inputs
- Available commands
- Valve open and close · Communication timeout · Modbus address
- Compatible models
- VX8i · VX12i
- Last updated
Registers (31)
31 read, 10 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Output 1 | Read and write | ||||
| Output 2 | Read and write | ||||
| Output 3 | Read and write | ||||
| Output 4 | Read and write | ||||
| Output 5 | Read and write | ||||
| Output 6 | Read and write | ||||
| Output 7 | Read and write | ||||
| Output 8 | Read and write | ||||
| Analog Input 1 | Read | ||||
| Analog Input 2 | Read | ||||
| Analog Input 3 | Read | ||||
| Analog Input 4 | Read | ||||
| Analog Input 1 Float | Read | ||||
| Analog Input 2 Float | Read | ||||
| Analog Input 3 Float | Read | ||||
| Analog Input 4 Float | Read | ||||
| Communication Timeout | s | Read and write | |||
| Output 1 Closure Count | Read | ||||
| Output 2 Closure Count | Read | ||||
| Output 3 Closure Count | Read | ||||
| Output 4 Closure Count | Read | ||||
| Output 5 Closure Count | Read | ||||
| Output 6 Closure Count | Read | ||||
| Output 7 Closure Count | Read | ||||
| Output 8 Closure Count | Read | ||||
| 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
- See which irrigation zones are open on one ModbusCloud dashboard, next to climate and water values.
- Open or close a zone valve from the portal for a manual watering or a flush.
- Use automations on a schedule to open and close a zone valve at set times.
- Follow the closure count per output to see how often each zone switched over 365 days of history.
- Log the analog inputs of a VX12i and get an email when a value crosses your threshold.
Installation
Wire the valves to outputs O1 to O8 and the shared ground terminals; 3-wire ball valves also use the 24 V terminals. Connect a 24 Vdc supply of up to 2.5 A.
Set the output mode with the mode button: AC (pulsed, factory default) for diaphragm valves, DC for DC valves.
Connect the GrowNET port to an Agrowtek LX2 ModLINK, directly or through an HX8 hub, and wire TX/RX+ and TX/RX- of the LX2 to the RS485 terminals of the ModbusCloud Gateway. Terminate the bus.
Give the controller its own address from 1 to 247 with the AgrowLINK utility, or write it at broadcast address 254 while it is the only device on the bus.
In ModbusCloud, add a Modbus device with protocol RTU, the address, 19200 baud, 8 data bits, no parity and 1 stop bit, and import this template. On a VX8i, remove the analog input registers.
Things to watch for
The valve controller does not answer through the LX2. What should I check?
Check 19200 baud, no parity, 1 stop bit and the controller 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 give every GrowNET device behind the LX2 its own address.
The controller is online, but the output LEDs stay off. Why?
The board takes its communication power from the RJ45 cable, but the valves run on the external 24 Vdc supply. Check that the supply has mains power and delivers 24 Vdc.
Switching one valve turns all valves off, or the LEDs flash.
One valve has a shorted coil that trips the overcurrent protection of the supply again and again. Measure the solenoid coils: 20 to 40 ohm is normal; below 10 ohm the coil is shorted and must be replaced.
The valves close by themselves after a while.
Check Communication Timeout: the VXi turns its outputs off when the master sends nothing for that many seconds. If ModbusCloud reads the controller less often than that, valves close between reads. Set the timeout longer than the read interval of the Modbus device.
How do I open a valve from ModbusCloud?
Write 1 to the output coil to switch the valve on and 0 to switch it off. Keep the timeout longer than the read interval, or the controller closes the valves between reads. Writing is off per gateway by default; request it for the gateway in the portal.
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