An expanding dairy operation required a dependable replacement for an unsupported LoRa-based water tank monitoring system. The solution needed to handle both powered and unpowered remote tank locations, transmit data over significant distances with obstructions, and provide a clear path for future expansion. A system combining specialized submersible sensors with a versatile wireless-to-Ethernet gateway was implemented to meet these demanding agricultural application requirements.
- Customer Requirement: Monitor water levels in two large, remote underground fresh and grey water tanks, one without a local power source.
- Wireless Communication: Needed a reliable, long-range wireless link to a central control PC, bypassing Wi-Fi limitations.
- Product Solution: Utilized an SLS-A series submersible sensor with a battery-powered IWPT-Node mV input wireless transmitter.
- Network Integration: Data is received by an IWR-PORT gateway, which connects to the existing LAN via Ethernet for centralized monitoring and control.
- Scalability: The system supports up to 128 sensor nodes, providing a clear upgrade path for future tank installations.
An IT consultant, on behalf of a client in the agricultural sector, sought a robust and scalable solution for monitoring water levels in large underground tanks at an expanding dairy farm. The existing system, which utilized LoRa technology for communication between tank depth pressure sensors and an Ethernet gateway, was proving unreliable due to a lack of manufacturer support. The immediate requirement was to monitor two separate tanks—one 5 feet deep containing 14,000 gallons of fresh water and another 7 feet deep with 10,000 gallons of grey water. These tanks were located in separate buildings approximately 100 yards apart, with the monitoring and control PC situated a further 100 yards from the closest tank. A key challenge was the power availability; while the fresh water tank location had access to power, the grey water tank did not. The client also had ambitious future expansion plans, intending to add more tanks up to 400 yards away, necessitating a wireless technology capable of long-range, reliable communication through environments with significant Wi-Fi obstruction.
The proposed solution centered on integrating robust, specialized sensors with a flexible wireless communication network. At the core of the measurement system is the SLS-A series submersible level sensor. This sensor is specifically designed for continuous immersion and features a piezoresistive silicon sensing element protected by a rugged 316 stainless steel housing and a high-integrity overmolded cable assembly, making it ideal for both fresh and grey water applications. For the unpowered tank, the millivolt output version of the SLS-A sensor was selected due to its very low power consumption, making it perfect for battery-powered operation. This sensor is connected to an IWTP-Node series millivolt input wireless transmitter, which is engineered to power the sensor, take a reading, and transmit it wirelessly. The IWTP-Node provides the necessary excitation voltage for the sensor and is powered by its own long-lasting 3.6V lithium battery, completely eliminating the need for a local power source at the tank.
The data from the wireless transmitter is sent using a 2.4 GHz frequency band, capable of line-of-sight ranges up to 500 meters, to an IWR-PORT series wireless gateway. This gateway acts as the central receiver and network coordinator, capable of handling data from up to 128 individual wireless sensors, ensuring ample capacity for the client’s planned expansion. The IWR-PORT is equipped with an Ethernet port, allowing seamless integration into the farm’s existing local area network (LAN). This enables the collected level data to be transmitted to a central PC for monitoring, control, and data logging. The gateway uses the standard MODBUS TCP/IP protocol, ensuring compatibility with a wide range of industrial automation and SCADA software. This modular and scalable system not only resolved the immediate monitoring needs for the two disparate tanks but also provided a future-proof platform ready to accommodate the farm’s growth.
IWR-PORT Wireless Sensors to Ethernet Gateway Receiver
- Part No: IWR-PORT-E
- Wireless Receiver: Ethernet port with Modbus TCP
- Optional Extras: 6dBi external mount antenna for increased wireless range, 5m external mount antenna cable assembly
IWPT-Node mV Input Wireless Transmitter
- Part No: IWPT-Node
- Wireless Transmitters: Analogue Signal Input
- Analogue Signal Input: mV strain gauge input
SLS-A Submersible Level Sensor
- Part No: SLS-AA-A005-BV-0250G-00
- Level Range: 0 to 7 ftWG
- Range Type: Gauge, Vented Reference
- Output Signal: 2mV/V
- Accuracy Class: 0.25%
- Cable Type: PUR
- Cable Length: 16
- Cable Length Units: Feet (ft)
- Housing Material: 316 Stainless Steel
- Seal Material: Viton
- Diaphragm Material: 316 Stainless Steel