How to buy access control controller nine points suggest four misunderstandings

The access control controller is the core part of the access control system and the soul of the access control system. The quality and performance of the access controller directly affect the stability of the access control system, and the stability of the system directly affects the work and life order of the users of the access control system, and even affects the safety of life and property.

At present, there are many access controller products on the Chinese market, and the functions are almost the same, but the quality is uneven. Therefore, product selection is particularly important for engineering companies. So how to choose a high-quality access controller? The stability of the access control system, the convenience of operation, and the practicality of functions are important factors and core standards for the evaluation of access control controllers.

Suggestion 1: Choose an access controller with anti-crash and self-check circuit design
If the access control controller crashes, it will make the user unable to open the door or close the door, which will bring great inconvenience to the customer. At the same time, it will increase the maintenance amount and maintenance cost of the engineering company. The access control controller must be installed with a reset chip or selected CPU with reset function, generally 51 series CPU does not have reset function, need to install reset chip. At the same time, it must have a self-checking function. If the circuit crashes due to interference or abnormal conditions, the system can self-check and start itself in an instant.

Recommendation 2: Access controller with three-level lightning protection circuit design
Because the communication lines of the access control controller are distributed and are easily attacked by induction lightning, the access control controller must be designed for lightning protection. We suggest adopting a three-level lightning protection design, first releasing the large current and high voltage generated by the lightning strike through the discharge tube, and clamping the current and voltage into the circuit through the inductance and resistance circuit. Then the TVS high-speed discharge tube discharges the residual current and voltage at high speed before it damages the circuit. The lightning protection index requires that 4000V induction lightning has 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 will be correspondingly high. Some products advertise that they also have a 1500V lightning protection capability. In fact, this indicator is all the chips themselves have, and they do not have the ability to prevent lightning strikes and surges.

Recommendation 3: The storage capacity of the registration card authority should be large, and the storage capacity of offline recording should also be large enough. The storage chip needs to use a non-volatile storage chip.
It is recommended that the registration card authority needs to reach 20,000, and the offline storage record should reach 100,000, which is suitable for the storage capacity requirements of most customers and facilitates attendance statistics. Non-volatile memory chips such as Flash must be used, and the information will not be lost when power is off or impacted. If the RAM + battery mode is used, the information may be lost if the battery is dead or loose, or if it is subjected to current shock. The access control system may fail.

Recommendation 4: The design of the communication circuit should have a self-detection function. It is suitable for the needs of large-scale system networking. The networking of access controllers usually adopts the 485 industrial bus structure. Generally, many manufacturers choose max 485 487 or 1487 chips for cost savings. The load capacity is weak, usually the maximum load capacity is 32 devices, and if a communication chip in the bus is damaged, it 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 communication chips and integrated circuits similar to max3080. The circuit has a self-test function. If the chip is damaged, the system will automatically disconnect the connection to him, so that the control devices on other buses can communicate normally.

Recommendation 5: The application should be simple and practical, and easy to operate
If the control program is applied, it will undoubtedly increase the cost and time of the training of the engineering company to the customer. If the customer is not easy to master the operation of the software, it will be angry that the service attitude of the engineering company will have a bad influence on the collection and renewal of the order. Customers who do not understand the software are also prone to misuse, resulting in practical inconvenience. Therefore, we suggest that the engineering company must pay attention to whether the operation of the software is simple, intuitive and convenient when selecting the access controller. One-sided emphasis on powerful functions is not suitable for promotion.

Recommendation 6: It is advisable to use high-power well-known brand relays, and the output end has current feedback to protect 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 a momentary current flows through each opening and closing. If the relay capacity is too small, the instantaneous current may exceed the relay capacity, which will quickly damage the relay. In general, the relay capacity should be more than 3 times the peak current of the electric lock. It is recommended to use a 7A rated working current relay. The output end is usually an inductive device connected to a large current such as an electric lock. The instantaneous on and off will produce a feedback current impact, so the output end should be protected by components such as varistor or reverse diode.

Recommendation 7: Card reader input circuit needs anti-surge and anti-misconnection protection
When the construction company is constructing, it is often connected or debugged with electricity. It may be caused by accidental negligence, wrong connection of the card reader wire or accidental local short circuit. If there is no protection against surge and wrong connection, it is easy to burn The central processing chip causes damage to the entire controller and needs to be sent back to the manufacturer for repair, which may delay the construction period and increase construction costs. Good protection can prevent the circuit from being burned even if the power is connected to the data terminal of the card reader. Anti-surge dynamic voltage protection can prevent the normal operation of the controller from being affected by the quality of the card reader.

Recommendation 8: It is recommended that the engineering company find the controller manufacturer or the agent designated by the manufacturer to purchase
It is only possible to purchase directly from the manufacturer or the agent designated by the manufacturer, or to complete powerful technical services, and to ensure perfect after-sales service, and reliable follow-up research and development capabilities to ensure the continuity and advancedness of the product. Buying controllers from other channels may have lower prices, but technical support and after-sales service may not be enough.

Recommendation 9: Manufacturers need to provide authoritative quality certification
The manufacturer needs to provide an authoritative ISO9001 quality certification certificate and a product test report from a government quality supervision agency. And pay attention to verify the authenticity of these documents. The quality of products with corresponding third-party certification and supervision will be guaranteed.

Several misunderstandings when choosing an access controller:

Myth 1: Imported access controllers will be better. Imported controllers are very good in product stability and maturity. However, the price is expensive, and due to regional differences, the timeliness of the service will be poor, and the cost of the service is relatively high. At the same time, due to differences in cultural backgrounds, the needs and requirements of foreign users for access control are different from China's national conditions. Many functions are simply not suitable for China's national conditions and the needs of Chinese users. Of course, many access control controller manufacturers in China have small production scales, weak design capabilities, and few successful application cases. Engineering companies should also choose carefully. In order to promote their own products, many access control controller manufacturers in China conduct deceptive sales under the guise of manufacturing in countries such as Taiwan, the United States and Canada. In fact, the quality of the products is very problematic. Engineers should also treat this phenomenon with caution.

Myth 2: The wider the compatibility of the card reader, the better
Some controllers claim to be compatible with various formats of card readers, such as 485 format ABA format wiegand 37 40 and other format card readers, in fact, it is not necessary, although these formats have some advantages in part, but do not meet international standards , For future upgrades and expansion and anti-interference brought trouble, we insist on practical and stable compliance with the standard is the best principle, it is recommended that you only need to comply with the international standard reader 26bit Wiegand on it, imported access control controller 90 % Is in line with this standard.

Myth 3: The more powerful the better
Many domestic controllers advertise how powerful their products are. One-sided exaggeration of the effect of functions on access control is actually the most important for the stability of access control and simple operation of functions. We recommend shielding the powerful extension functions, and the customers need to provide them to meet their needs. Some functions that are not used by customers should not be recommended to customers. This can reduce the cost of training and maintenance, and customers are also happy with their use. .

Myth 4: The more expensive the better, or the cheaper the better
Good cost-effective products are the best products. The expensive product may be because its output is not high, or the cost of advertising is too high, not necessarily high product value. Cheap products may also be the one-sided pursuit of low cost, reduced investment in protection circuits, or the use of inferior and second-hand chips. Therefore, the engineering firm must keep its eyes open and make a reasonable assessment of the product's performance-price ratio.