Access controller to buy errors
Misunderstanding 1: The imported access controller will be better.
The imported controller is very good in product stability and maturity. However, the price is expensive, and because of geographical disparity, the timeliness of the service will not be good, and the service cost will be high. At the same time, due to the differences in cultural background, the foreign users' needs and requirements for access control and management are different from China's national conditions. Many features are simply not suitable for China's national conditions and the needs of Chinese users. Of course, many Chinese access controller manufacturers have small production scales and weak design capabilities. There are few successful application cases, and project companies should also choose carefully. Many Chinese access controller manufacturers, in order to sell their own products, use fraudulent sales made in Taiwan, the United States, Canada, and other countries. In fact, product quality has great problems. This phenomenon should also be treated with caution.
Misunderstanding 2: The reader's compatibility is as wide as possible
Some controllers claim to be compatible with readers of various formats, such as the 485 format WIEC format readers such as wiegand3740. In fact, it is not necessary. Although these formats have certain advantages in local areas, they do not conform to international standards. In the future, upgrading and expansion and anti-jamming have brought troubles. We adhere to the principle of practical stability and compliance with standards. It is recommended that you only need a card reader that complies with the international standards of wiegand26bit. 90% of the imported access controllers are in compliance. This standard.
Misunderstanding 3: The stronger the function, the better.
Many domestic controllers advertise how powerful their products are, and they exaggerate the function of access control functions. Actually, it is the most important for the stability of access control and the simple and functional operation. We propose to shield the powerful extension function, and customers need to provide it to meet their needs. Some functions that customers do not use should not be recommended to customers. This can reduce the cost and maintenance costs of training, and customers can also use it freely. .
Misunderstanding 4: The more expensive the price the better or the cheaper the better.
A good, cost-effective product is the best product. The expensive product may be because his output is not high, or the cost of advertising is too high, it does not necessarily mean that the value of the product is high. Cheaper products may also be the one-sided pursuit of low-cost, reduced investment in protection circuits, or the use of inferior and used chips. Therefore, the contractor must keep his eyes open to make a reasonable assessment of the product's performance and price ratio.
Access controller purchase advice
Recommendation one: Choose the access controller with anti-crash and self-test circuit design
If the access controller crashes, it will make the user unable to open the door or close the door, causing great inconvenience to the customer. At the same time, it also increases the maintenance and maintenance costs of the engineering company. The access controller must be installed with a reset chip or used. CPUs with reset function, generally the 51 series CPUs do not have a reset function, and a reset chip is required. At the same time, it must have a self-test function. If the circuit crashes due to interference or abnormal conditions, the system can self-check and perform self-start in an instant.
Recommendation two: access controller with three levels of lightning protection circuit design
Because the communication circuit of the access controller is distributed and vulnerable to inductive lightning, the access controller must be designed for lightning protection. We propose to adopt three-level lightning protection design. First discharge the large current and high voltage generated by the lightning strike through the discharge tube, and clamp the current and voltage into the circuit through the inductance and resistance circuits. The TVS high-speed discharge tube then releases residual current and voltage at high speed before it can damage the circuit. The lightning protection index requires 4000V induction lightning to have no damage to the equipment for 50 consecutive times. The lightning protection index is high, and the anti-surge and anti-static capabilities of the equipment are correspondingly high. Some products advertise that they also have a 1500V lightning protection capability. In fact, this indicator is available on all chips and does not have the ability to prevent lightning and surge.
Recommendation 3: The storage capacity of registered cards must be large, and the storage capacity of off-line recording should be large enough. The non-volatile memory chips must be used for memory chips.
It is recommended that the number of registered card rights need to reach 20,000, and the number of offline storage records should be 100,000. This can be suitable for the vast majority of customers' requirements for storage capacity, facilitating attendance statistics. Must use Flash and other non-volatile memory chips, power down or shock information will not be lost. If the RAM battery mode is used, information may be lost if the battery is dead or loose, or if there is current shock. The access control system may fail.
Recommendation 4: The application should be simple and practical, easy to operate
If the application of the control program, will undoubtedly increase the engineering company's training costs and time for customers, customers can not easily master the software operation will be angry with the engineering service attitude of the collection and renewal will have a bad influence. Customers do not understand the software and can easily cause misuse, causing practical inconvenience. Therefore, we recommend that when choosing an access controller, the engineering company must pay attention to whether the software operation is simple, intuitive and convenient. One-sided emphasis on powerful features is not suitable for promotion.
Recommendation 5: The design of the communication circuit should have a self-detection function and meet the needs of large-scale system networking
The access controller's network is usually networked using 485 industrial bus structure. Usually, many manufacturers choose max485487 or 1487 chips for cost saving. These chips have weak load capacity, usually the maximum load capacity is 32 devices, and if there is a communication in the bus Damage to the chip will affect the communication of the entire communication line, and it is impossible to find out which controller chip is damaged. We recommend using high-end communications chips and integrated circuits similar to the MAX3080. The circuit is equipped with a self-test function. If the chip is damaged, the system will automatically disconnect the connection to it, so that the control devices on other buses can communicate normally.
Recommendation 6: It is recommended to use high-power, well-known brands of relays with current feedback protection at the output
The output of the access controller is controlled by the relay. When the controller is working, the relay should be opened and closed frequently, and each moment of opening and closing has a transient current through. If the relay capacity is too small, the instantaneous current may exceed the capacity of the relay, and the relay will be damaged soon. In general, the relay capacity should be more than 3 times the peak current of the electric lock. It is recommended to use a relay rated at 7A. The output terminal is usually an inductive device with large current such as an electric lock. Instantaneous on-off will generate the impact of the feedback current. Therefore, the output terminal should be protected by varistors or reverse diodes.
Recommendation 7: It is recommended that the project company find the manufacturer of the controller or the agent designated by the manufacturer to purchase only the agents directly to the manufacturer or the manufacturer to purchase the product. It is possible or perfect to provide powerful technical services. The perfect after-sales service is guaranteed. Reliable follow-up R&D capabilities to ensure product continuity and advancement. Buying controllers from other sources may have lower prices, but technical support and after-sales services may not be enough.
Recommendation No. 8: Reader Input Circuit Needs Surge Protection, Misconnection Protection
When the contractor works, it is often live with wiring or debugging. It may be due to accidental oversight, incorrect reading of the reader's cable or accidental local short circuit. If there is no surge protection and misconnection protection, it is very easy to burn the central processing chip and cause the entire controller to be damaged. It is necessary to send it back to the manufacturer for repairs, which may delay the construction period and increase the construction cost. Good protection can prevent the circuit from being burned out even if the power supply is connected to the data terminal of the card reader. The surge-proof dynamic voltage protection can prevent the controller from affecting the normal operation of the controller due to the quality of the card reader.
Recommendation 9: Manufacturers need to provide authoritative quality certification
Manufacturers need to provide authoritative ISO9001 quality certification certificates and product inspection reports from government quality regulatory agencies. And pay attention to verify the authenticity of these documents. The quality of the products certified and supervised by the corresponding third parties will be guaranteed.
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