How to choose a best suitable access control controller?
The access controller procurement guidelines: 7 recommendations.
The access controller is the core part of the access control system, is also the soul of the system. The quality and performance of the access controller directly affect the stability of the access control system, and the stability of the system will directly affect the access control system users work and life order and even affect the safety of life and property.
At present, many access control products in the global market, the function is almost the same, but the quality is uneven. So the product selection is particularly important. So how to choose high-quality access control controller? The stability of the access control system, the convenience of operation, the practicality of the function is an important factor and the core standard in the evaluation of the access controller.
Recommendation 1: Purchase access control controller with anti-crash and self-test circuit design.
If the access controller crashes, will make the user cannot open the door or close the door, bring great inconvenience to customers, but also increase the maintenance and maintenance costs of the project, the access controller must install the reset chip or use CPU with reset function, the general 51 series CPU doesn’t have reset function, you need to install the reset chip. At the same time, must have a self-test function, if the circuit because of interference or abnormal circumstances crash, the system can self-test and self-starting in an instant S
Recommendation II: Choose access control controller with three level anti-lightning protection circuit design.
Because of the access control controller communication lines are distributed, vulnerable to the induction of lightning attack, so the access controller must be anti-lightning protection design.It is recommended to use three level lightning protection design.
Recommendation 3: The storage capacity of registered card permissions should be large, the storage capacity of offline records should be large enough, the storage chip should use nonvolatile memory chip
The proposed registration card permissions need to reach 20,000, off-line storage records are the best reach to 100,000, it can be suitable for the majority of customers demands on storage capacity, easy attendance statistics. Must use Flash and other non-volatile memory chip, Power-down or shock information will not be lost.If the RAM + battery mode, if the battery is no electricity or loose, or by the impact of current information may be lost. Access control system is likely to fail.
Recommendation 4: The design of the communication circuit should have self-test function, suitable for large system networking needs.
Access control controller networking is usually 485 industrial bus structure, usually many manufacturers from the cost savings to consider the choice of max 485 487 or 1487 chip, but these chips load capacity are weak, usually the maximum load capacity is 32 devices, and if there is a communication chip damage will affect the entire communication lines of communication, and can not find out which controller chip damage.It is recommended similar to max3080 similar high-grade communication chip and an integrated circuit, the circuit has self-test function, if the chip is damaged, The system will automatically disconnect the connection to him, making the normal communication to other control devices on the bus.
Recommendation 5: The application should be simple and practical, easy to operate.
If the application program is complex, will undoubtedly increase the cost of training and time for the project and the customer, the customer is not easy to grasp the operation of the software, will be angry in the service attitude of the project, receipt and renewal will have a bad impact. Customers do not understand software can easily cause misoperation, causing the utility is not convenient taking engineering.Therefore, it is recommended that engineers must pay attention to the operation of the software is simple and intuitive and convenient.A one-sided emphasis on functional is not suitable for promotion.
Recommendation 6: should use relays of high-power well-known brands, and the output current feedback protection.
The output of the access controller is controlled by the relay. When the controller is in operation, the relay must be opened and closed frequently, and each time the opening and closing has an instantaneous current through. If the relay capacity is too small, the instantaneous current may exceed the capacity of the relay and will soon damage the relay. The general situation relay capacity should be greater than the electric lock peak current 3 times or more, it is recommended to use 7A rated current relay. The output is usually connected to the electric lock and other high current inductive devices, an instantaneous break will produce feedback current impact, so The output should be a varistor or reverse diode and other components to be protected.
Recommendation 7: card reader input circuit needs surge protection and error proofing Engineering construction, often charged for wiring or debugging, may be due to accidental negligence, then the wrong card reader line or accidentally cause local short circuit, if there is no anti-surge and anti-wrong protection, it is easy to burn The central processing chip, resulting in damage to the entire controller failure, need to return to the factory maintenance, may delay the construction period, improve construction costs. Good protection can make even if the power supply connected to the reader data side will not burn the circuit through the surge Dynamic voltage protection can be avoided because the reader quality problems affect the normal operation of the controller