Application of ZigBee technology in ultrasonic water meter
Ultrasonic water meters can be installed horizontally or vertically, but no matter which direction, the axis of the measuring electrode must be kept horizontal, and the display must be horizontal. The display circuit board can be rotated 90° or 180° and then reinstalled. When installing the meter, the measuring tube should always be filled with the measured medium during the whole measurement process. In order to obtain zero flow rate during zero point calibration, a shut-off valve must be installed upstream or downstream of the flowmeter. The upstream straight pipe section of the flowmeter should be greater than or equal to 5D, and the downstream straight pipe section should be greater than or equal to 2D (calculated from the electrode axis). When installing the flowmeter, avoid places with vibration and impact.
Their grounding rings must be installed on both sides of the flowmeter. The grounding ring, flow meter and measurement ground M must be conductive. Flange connection ground bolts must be made of insulating material with bushings and thermal insulation. Measure grounding M, it is recommended to ground separately. If it is difficult, it can be connected to a grounded pipeline flange. When there is a measurement grounding M, do not connect the protective grounding PE terminal to the protective grounding wire of the power cable. Because it also plays a role in protecting grounding. The power supply and output signal wires should be laid separately.
Application of ZigBee technology in ultrasonic water meter:
Each ZigBee network node can not only be connected to monitoring objects, such as ultrasonic water meters, for direct data collection and monitoring, but also can automatically transfer data from other network nodes; in addition, each ZigBee network node (FFD) ) Can also wirelessly connect with multiple isolated child nodes (RFD) that do not undertake the task of network information transfer within the coverage of its own signal. ZigBee relies on an independent working node to form a star, string (tree), or mesh network through wireless communication. Therefore, the function of each node is not the same. Among them, RFD is a semi-functional node or sensor node; FFD is a full The function node is the network coordinator node, which is responsible for communicating with the controlled RFD node, collecting data and publishing control, or playing the role of communication routing; each node forms a wireless self-organizing network system through wireless communication.
The main advantages of ZigBee technology:
(1) Low power consumption: Two AA batteries support up to 6 months to 2 years of use.
(2) Reliability: The collision avoidance mechanism is adopted; the node modules have the function of automatic dynamic networking, and information is transmitted through automatic routing in the entire ZigBee network, thereby ensuring the reliability of information transmission.
(3) Low cost: ZigBee module is low in price.
(4) Short delay: Optimized for delay-sensitive applications, the communication delay and the delay of activation from the dormant state are both very short.
(5) Short distance: The communication distance is from a few centimeters to a few hundred meters. After the transmission power is increased, it can be increased to 1~3km. If through routing and communication relay between nodes, you can transmit a longer distance.
