Talking about the functional requirements and design scheme of flow meter based on CPU card

Abstract: Talking about the functional requirements and design information of flow meter based on CPU card is provided by excellent flow meter and flow meter manufacturers. Abstract: IC card is a kind of semiconductor card, which has been more and more used in information automation, that is, people's life, but it also has some shortcomings. The key cannot be sent to the application side (gas. More flowmeter manufacturers select models and price quotations. You are welcome to inquire. The following is a brief introduction to the functional requirements and design solutions of flowmeters based on CPU cards. The IC card is a kind of semiconductor card. It has been more and more used in information automation, that is, people's lives, but it also has some shortcomings. Due to the technical limitations of the logic encryption card, the key of the product supplier cannot be disclosed to the application party (gas company). , so the application side cannot grasp the core security, the system security depends on the product supplier, and the logic encryption cards of different models are incompatible with each other, resulting in the incompatibility of the chip data storage solutions of different manufacturers. It brings a variety of complication in the management of keys and key algorithms. The article discusses some requirements for design. Introduction IC card is a kind of semiconductor card, which uses microelectronics technology to store and process information. Since the birth of the first IC card in 1970, IC card has experienced four eras: general memory card, encrypted memory card, CPU card and super smart card. IC card is the result of the comprehensive development of multi-disciplinary technology, and its application has become a national scientific and technological development. One of the signs of the level. IC cards are more and more widely used in urban gas flow metering. Before CPU card flowmeters, logic encryption cards were widely used. Due to the technical limitations of logic encryption cards, the encryption of product suppliers The key cannot be disclosed to the application side (gas company), so the application side cannot master the core security. The system security depends on the product supplier, and different types of logic encryption cards are incompatible with each other, resulting in incompatible chip data storage solutions from different manufacturers. When the application side uses multiple card tables, it will bring complications in the management of various keys and key algorithms. The CPU card is also called a smart card. The card has its own CPU, large program capacity and data capacity, and has encryption and decryption. Algorithm co-processor, fast calculation speed. Using CPU card and formulating a unified technical specification, gas companies can fully grasp the technical core and key algorithm of CPU card flowmeter, ensure accurate gas measurement, and realize gas purchase before use It can be seen that the key to the successful application of the CPU card industrial flowmeter is a well-designed CPU card key system. 1. Functional requirements of the CPU card flowmeter At present, the new CPU card flowmeter is a set of measurement A flowmeter that integrates a base meter, an electronic meter head and a control valve. Previously, the CPU card flowmeter was usually formed by the integrator electrically connecting the flowmeter and the IC card control valve, and the flowmeter was measuring a certain amount (usually 1m3 ), output a pulse to the IC card control valve, the IC card control valve will deduct, when the deduction exceeds the allowable overdraft amount, the control valve will be closed. For this method, the reliability of the electrical connection is the key, and the situation that often occurs is The deduction is not synchronized, and the amount of flowmeter running is not the same as the amount deducted by the IC card control valve, resulting in volume disputes. Therefore, in terms of the function of the CPU card flowmeter, the integrated flowmeter is the trend of development. In gas trade, the user purchases gas through the CPU card and recharges the gas into the flow meter. The gas company manages the user's gas consumption through the CPU card. The CPU card plays a key role for the user and the gas company. In addition, when the upstream gas price fluctuates, the gas company can adjust the gas price through the CPU card or other methods in time. To sum up, the CPU card should at least save the following information: user information, gas company logo, gas purchase volume and number of gas purchases, as well as the key group designed for security needs, and the card logos of different function cards. In order to avoid the loss of data in the card caused by abnormal operation, the main operation process can also be recorded in the card file. After the abnormal operation, the card can be inserted again to resume the normal operation. 2. Overall design of key system The design of this key system adopts three-level distributed four-level key method, from the root key to the final application card key, as shown in Figure 1. Figure 1 Key system Figure 2.1 Key management It can be seen from Figure 1 that in the key system, each application card is at the bottom of the system, and its key is obtained by dispersing the key according to the parent card at the upper level and the dispersion factor. of. Therefore, it is necessary to strengthen the management of the mother card. In order to prevent the unpredictable physical damage of the mother cards at all levels in the application, it is necessary to back up the mother cards at all levels and set the management authority according to the needs of the unit. 2.2 Key Dispersion When performing cryptographic operations, a data encryption standard (data encryption standard, DES) or a 3DES algorithm can be selected according to the key length. Generally speaking, the key length is 8B with DES,16B uses 3DES algorithm. The logic block diagram of these two algorithms is shown in Figure 2. Figure 2 Operational logic block diagram 2.3DES Algorithm DES algorithm is a symmetric cryptosystem, which was successfully researched and published by IBM in 1975, creating a precedent for the disclosure of all algorithms.

Beijing Sincerity Automatic Equipment Co., Ltd is dedicated to servicing our customers with a wide array of high-quality service and products.

Now you can buy cheap at wholesale price at Beijing Sincerity Automatic Equipment Co., Ltd! Do visit Sincerity Flow Meter for great deals!

mass flow meter are raising the stakes of social marketing, but they also ease the sales process by providing ways for rosemount coriolis mass flow meter to effectively interact with customers.

Beijing Sincerity Automatic Equipment Co., Ltd provides the ideal conditions for business creation – access to cash, human capital and affordable office space, for instance – can help new ventures not only take off but also thrive.

Beijing Sincerity Automatic Equipment Co., Ltd deems mass flow meter as evolutionary rather than revolutionary. We've always had these 'social commerce' marketplaces in some form.