Nine suggestions

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 control controller directly affect the stability of the access control system, and the stability of the system will directly affect the work and life order of the user of the access control system, and even affect the safety of life and property.

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

Recommendation 1: Choose an access control controller with anti-crash and self-check circuit design 

If the access controller is dead, it will make the user can not open the door or can not close the door, which brings great inconvenience to customers, but also increases the maintenance amount and maintenance cost of the engineer, the access controller must be installed with a reset chip or a CPU with a reset function, the general 51 series CPU does not have a reset function, need to install a reset chip. At the same time, it must have a self-check function, if the circuit crashes due to interference or abnormal conditions, the system can self-check and self-start in an instant.

Recommendation 2: Access controllers with level 3 lightning protection circuit design

Because the communication line of the access control controller is distributed, it is easy to suffer from the invasion of inductive lightning, so the access control controller must be lightning protection design, we recommend the use of three-level lightning protection design, the first through the discharge tube will be generated by lightning current and high voltage release, through the inductance and resistance circuit clamp into the circuit current and voltage. Then the residual current and voltage are released at high speed through the TVS high-speed discharge tube before it causes damage to the circuit. Lightning protection Indicator 4000V Inductive thunder for 50 consecutive times does not damage the device. The lightning protection index is high, and the surge and antistatic capacity of the equipment will be correspondingly high. Some products advertise that they also have 1500V lightning protection ability, in fact, this indicator is that all the chips themselves have, do not have the ability to prevent lightning and surge.

Recommendation 3: The registration card authority storage capacity should be large, the offline record storage capacity should be large enough, the memory chip needs to use non-volatile memory chip 

It is recommended that the registration card authority needs to reach more than 10,000, offline storage records reach 100,000, which can be suitable for the vast majority of customers on the storage capacity requirements, convenient attendance statistics. Be sure to use non-volatile memory chips such as Flash, power failure or impact information will not be lost, if the RAM+ battery mode is used, if the battery is out of power or loose, or by current impact information may be lost, the access control system may fail.

Recommendation 4: The design of the communication circuit should have self-detection function, suitable for the needs of large system networking

Access controller networking usually uses 485 industrial bus structure networking, usually many manufacturers from cost saving considerations, choose max485487 or 1487 chip, these chips load capacity is weak, usually the maximum load capacity is 32 devices, and if the bus if there is a communication chip damage will affect the entire communication line communication, And can not find exactly which controller chip is damaged. We recommend using a high-end communication chip and integrated circuit similar to the max3080, which has a self-check function, if the chip is damaged, the system will automatically disconnect the connection to it, so that the control device on the other bus can communicate normally.

Recommendation5: Applications should be simple and easy to use

If the control program is applied, it will undoubtedly increase the training cost and time of the engineer to the customer, and the customer is not easy to grasp the operation of the software, and will be angry at the service attitude of the engineer, which will bring bad effects on the collection and renewal of orders. Customers do not understand the software and it is easy to cause misoperation, resulting in practical inconvenience. Therefore, we suggest that engineers must pay attention to whether the operation of the software is simple and intuitive. One-sided emphasis on powerful functions is not suitable for promotion.

Recommendation 6: It is advisable to choose a high-power well-known brand relay, and the output end has current feedback protection

The output of the access controller is controlled by a relay. When the controller is working, the relay should be opened and closed frequently, and each time there is an instantaneous current through. If the relay capacity is too small, the instantaneous current may exceed the capacity of the relay, which will soon damage the relay. In general, the relay capacity should be more than 3 times the peak current of the electric lock, and it is recommended to choose a relay with 7A rated working current. The output end is usually an inductive device with a large current such as an electric lock, and the instantaneous on-off will produce the impact of the feedback current, so the output end should be protected by components such as varistor or reverse diode.

Recommendation 7: The input circuit of the card reader needs to be protected against surge and misconnection

When the engineer is in construction, it is often live wiring or debugging, which may cause local short circuit due to accidental negligence, connecting the wrong line of the card reader or accidentally. If there is no anti-surge and anti-error connection protection, it is easy to burn the central processing chip, resulting in damage and failure of the whole controller, which needs to be sent back to the manufacturer for maintenance. It may delay the construction period and increase the construction cost. Good protection can make even if the power is connected to the data end of the card reader will not burn out the circuit. By anti-surge dynamic voltage protection, the normal operation of the controller can be avoided due to the quality problems of the card reader.

Recommendation 8: It is recommended that the engineer find the controller manufacturer or the manufacturer's designated agent to buy

Only by directly looking for the manufacturer or the manufacturer's designated agent to buy it is possible or perfect strong technical service, perfect after-sales service is guaranteed, and there is a reliable follow-up research and development ability to ensure that the product has continuity and advancement. Buying the controller from other sources may have a lower price, but technical support and after-sales service may not be enough.

Recommendation 9: Manufacturers need to provide authoritative quality certification

Manufacturers are required to provide product testing reports from authoritative government quality supervision agencies. And pay attention to verify the authenticity of these documents, there are corresponding third-party certification and supervision of the quality of the product will be guaranteed.

Several errors in the purchase of access control

Misunderstanding 1: Imported access control will be better.

The imported controller is very good in the stability and maturity of the product, but the price is expensive, and due to the regional gap, the timeliness of the service will be bad, and the service cost is high. At the same time, due to the difference in cultural background, foreign users' needs and requirements for access management and 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 manufacturers in China have small production scale, weak design capacity, and few successful application cases, and engineers should also choose carefully. Many access control manufacturers in China, in order to promote their products, deceptive sales under the guise of manufacturing in Taiwan, the United States, Canada and other countries, in fact, product quality has a big problem, this phenomenon should also be treated with caution.

Misunderstanding 2: The wider the compatibility of the card reader, the better

Some controllers claim to be compatible with card readers in various formats, such as ABA format wiegand 37, 40, etc., but in fact, it is not necessary, although these formats have some local advantages. But does not meet international standards, for the future upgrade and expansion and anti-interference brought trouble, we adhere to the practical stability in line with the standard is the best principle, it is recommended that you only need to meet the international standard of wg26 card reader, imported access control 90% is in line with this standard.

Misunderstanding 3: The more powerful, the better

Many domestic controllers promote how powerful the functions of their products, one-sided exaggeration of the function of access control, in fact, for access control stability and functional practical operation is the most important. We suggest shielding the powerful extension functions and providing them only when customers need them to meet their needs. Some functions that customers do not use should not be recommended to customers, so that the cost of training and maintenance can be reduced, and customers can also use it satisfactorily.

Misunderstanding 4: The more expensive the better or the cheaper the better.

Good cost-effective products are the best products. Expensive products may be because their output is not high, or the cost of advertising is too high, does not necessarily mean that the product value is high. Cheap products may also be the manufacturer's one-sided pursuit of low costs and reduced protection

The input of the circuit, or the selection of inferior and second-hand chips. So the engineer must polish his eyes to make a reasonable evaluation of the performance price ratio of the product.