| The design is a measuring and controlling system of intelligence which is based on network and virtual instruments. It applies computers, TCP/IP technologies, virtual instruments technologies and advanced measuring and controlling methods in industry to the cold storage field. And it makes the non-industry fields get benefit from the prompt development of the industrial automation. It also makes the cold storage system automatically, and improves the controlling precision and efficiency of cold storage systems.It affords a reference for the reconstruction of old cold storages and the design of a new cold storage.By the help of a computer and a DAQ card (data acquisition card), the sub-system measures and controls the items such as temperature, humidity, concentration of CO2 and so on, and all the sub-systems are connected to the main controlling system by network, then a network cold storage measuring and controlling system is constructed. Both the main controlling system and the sub-systems use LabVIEW as a programming language, which makes it very convenient and fast to develop the software. The system adopts the construction of a universal measuring and controlling system. and the modification and expand of the calibrating and the controlling on each channel The calibration and controlling method of each channel can be modified and expanded dynamically, which makes the system satisfy various of demand in fact. In the hardware part of the sub-system, the MUXes are control by the DAQ card, and then they can scan the signal channels to measure and control. According to the theory of multiple tasks operating system, the system assign CPU time slice for every channel to process signals.The open interface and dynamic configuration make it very flexible. The system can measure and control many signals besides the temperature, humidity, concentration of CO2, and satisfy the increasing demand. The application of network makes it possible to measure and control a big cold storage. |
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