Hot water consumption is extremely high in both production and daily life, but commercially available water heaters typically only allow for fixed temperature settings and generally require on-site control. However, in many industrial settings, it is often necessary to control the operation of remote hot water systems to ensure stable hot water production and allow for real-time temperature adjustment. This paper designs a remote monitoring system based on a LON network using ordinary single-strand twisted-pair cable as the network physical medium to accomplish these functions. 1 Lonworks Bus and Neural Chip The Lonworks control network is one of the most popular fieldbuses currently available. Its core components are the neuron chip and the LonTalk communication protocol. The LonTalk communication protocol supports all seven layers of the OSI/RM model, enabling LON networks to have good interfaces and compatibility with other networks. It supports various topologies, and the communication medium can be selected from twisted-pair cable, power lines, infrared, fiber optics, coaxial cable, etc., making network cabling more convenient. The application uses an object-oriented design approach, exchanging data between nodes through network variables, simplifying network communication to parameter settings. This system uses two key components. (1) Neuron Chips Neuron chips use CMOS VLSI technology, which allows for the operation of inexpensive control networks. They mainly include two major series: MCI43150 and MCI43120. The main features of the neuron chip are: high integration, requiring fewer external components; three 8-bit CPUs with a selectable input clock range of 10-625Hz; on-chip memory; 11 programmable I/O pins (with 34 selectable operating modes); two 16-bit timers/counters; 15 soft timers; five network communication ports with three selectable modes (single-ended reflection, differential mode, and dedicated mode); firmware including LonTalk protocol conforming to OSI seven-layer protocol, I/O driver and event-driven multitasking scheduler; service pins for remote identification and diagnosis; 48-bit internal Neuron ID for unique identification of Neuron chip; In the two series, the 3120 chip contains E2PROM, RAM and ROM memory, while the 3150 chip has no internal ROM but has an interface to access external memory, and the memory can be flexibly configured according to the actual situation. (2) The transceiver provides the physical communication interface between the neuron chip and the Lonworks network. 2. Water Temperature Monitoring System Hardware Composition and Working Principle This system consists of two nodes: a monitoring node and an execution node. They are located at opposite ends of the LON network, as shown in Figure 1. This system uses single-strand twisted-pair cable as the network medium, and the transceiver is an Echelon FTT-10A model. Communication between the two nodes is achieved through network variables. In each node, a 3150 chip is used, along with an AT29C257 2KB Flash memory chip to store the neural chip firmware, including application programs, data, and communication protocols. The connection between the neural chip and the memory is shown in Figure 2. The monitoring node is located in the central control room and displays the real-time water temperature. Users can use it to set the water temperature for remote heating devices. The I/O circuit of the neural chip in the monitoring node is shown in Figure 3. In this circuit, the user adjusts the potentiometer to set the water temperature; the voltage obtained from the potentiometer is converted into a number between 0 and 100 after A/O conversion, sent to the execution node, and displayed on the first two digital tubes. The real-time water temperature transmitted from the execution node is displayed on the last two digital tubes. To fully utilize the chip's I/O ports, a shift counter 74HC595 is used to expand the I/O ports. The chip's serial output function is employed, with I/O8 as the clock signal, I/O9 as the data output port, and I/O6 as the data latch control terminal. An LCD display can replace the 8-segment digital tubes as needed. The execution node is located at the heater end. It detects the water temperature and sends the value to the monitoring node, receiving control temperature data from the monitoring node and starting/stopping the water heater as needed. The I/O circuit of the neural chip in the execution node is shown in Figure 4. In this circuit, the real-time water temperature is detected by a temperature sensor, converted to a value between 0 and 100 after A/D conversion, stored, and sent to the monitoring node. The neural chip compares the control temperature value received from the monitoring node with the detected temperature value. If the detected value is smaller, the relay is closed, and the heater starts working; if the detected value is larger, the relay is opened, and the heater stops working. To avoid repeated power-on and power-off operation of the heater, an acceptable temperature control accuracy range can be set. In this circuit, it is set to ±3℃, meaning that during heating, the relay is only disconnected when the detected temperature exceeds the control temperature by 3℃; when not heating, the relay is only closed when the detected temperature is below the control temperature by 3℃. 3. Software Design The software part of this system adopts an object-oriented programming method, defining the detection signal, control signal, and neural chip I/O as different objects, and programming with Neuron C. The programs for the monitoring node and execution node can be found on the website (www.dpi.com.cn). Conclusion This paper utilizes the Lonwork network to achieve long-distance node communication on a single-strand twisted-pair cable, designing and implementing the monitoring of remote water temperature. This system only involves temperature control; in practical applications, only simple circuits and program code need to be added to achieve control of other indicators such as pressure and oxygen content (e.g., in public bathrooms).