Why promote wireless communication technology
China's current smart card devices (IC card consumer machines, attendance machines, access control machines, etc.) have been in large-scale development history since the mid-1990s, and have experienced more than 10 years of large-scale development history. During this period, smart cards have undergone several upgrades, from contact IC cards have evolved into contactless IC cards, from memory cards to logical encryption cards and CPU cards. The device functions have also undergone several upgrades. However, its networking method is developing very slowly. Among them, more than 80% of the devices connected to the PC still use the RS485/RS422 network; a few devices start to build the TCP/IP communication module, using the five types of cable networking, but the cost is higher, the networking distance Closer (100 meters). The individual system uses the CAN bus, the cost is moderate, the networking distance is about 1000 meters, and the communication speed is better at 19.2-100 kbps.
At present, smart card devices using RS485 network communication have a maximum communication distance of 1200 meters, a communication rate of about 9.6-19.2 kbps, a half-duplex mode, and a number of networks of 128.
Within the Taiwan. Due to the lag of the networking method, the network communication bottleneck of the smart card device is generated. In particular, it is necessary to quickly solve the construction convenience, communication speed, communication distance and the like.
At present, smart card devices are limited by the way of communication, which brings great restrictions on the installation of devices; for example, in some densely used places, such as campus classrooms, factory workshops, etc., it is necessary to lay intensive networking lines, usually 1-2 cables are laid in each classroom, and hundreds of information points are laid on a campus. The cost of laying the lines is high and the construction period is long. In particular, the maintenance work caused by the line fault in the later stage is large, and the efficiency of finding the fault point is low.
For some existing sites such as campuses, factories, etc., due to insufficient consideration in the initial stage of construction, network pipelines have not been reserved. Only pipelines, excavations, etc. can be considered for re-laying pipelines. As a result, construction costs have far exceeded smart cards. Total equipment investment.
At present, the research on ZigBee network has a broad application prospect on smart card devices. And has the following characteristics:
1. Mature technology, the basis of ZigBee network is IEEE 802.15.4;
2, low cost, the main controller of ZigBee network generally uses SoC (system on chip), the peripheral circuit is simple, and the interface with the main processor (MCU) of the smart card device is convenient. Existing smart card device architectures can be easily implemented without major upgrades.
3. No need to apply for a wireless channel.
4. The communication radius can reach several hundred meters under the line of sight. The repeater can be designed to expand the communication distance by multiple times (the current scheme can extend the communication radius by 6 times to 2000 meters).
5, communication speed is fast, ZigBee network communication speed can reach 250kbps, and even higher, its speed greatly exceeds the RS485 network.
6. Smart card devices using ZigBee wireless network communication The maximum number of device communication in a single network is 750. This number can also be expanded (currently the number of limit networking is 62,500), and its networking capability greatly exceeds wired RS485 network, CAN network, etc. .
7, wireless communication has no line restrictions, the signal can easily penetrate the conductive objects such as walls, glass, wood, etc. After the equipment is in place, the wireless network channel is formed immediately, and the construction speed is fast. Once the network is built, all smart card devices can scale to any mobile and limited (up to 750) devices as long as they are within the wireless signal coverage.
8, wireless communication has no line restrictions, the signal can easily penetrate the conductive objects such as walls, glass, wood, etc. After the equipment is in place, the wireless network channel is formed immediately, and the construction speed is fast. After the network is built, as long as the wireless signal coverage, all smart card devices can achieve any mobile and device expansion; even the ultimate customer can directly purchase wireless smart card devices, self-organizing, no professional company construction. Wireless communication technology has pushed the application of smart card devices to a new milestone.
9, wireless communication can greatly reduce the use of cables, the average use of 50 meters of wire per machine calculation, the annual sales of 10,000 sets of equipment to save 500,000 meters of cable, if the use of five types of lines, save more than 1 million yuan Cable cost; if it is calculated at a wiring cost of 10 yuan per meter, it will save more than 5 million wiring costs. Under the policy of building a conservation-oriented society in the central government, the popularity of wireless smart card devices has obvious social benefits.
Jiangmen Merit Metal Electric Appliance Co.,Ltd. , https://www.meritbbq.com