What are the meanings of a series of symbols such as NC, NO, COM and PUSH?

A series of symbols of access control system have the following meanings:

Push: refers to short circuit to ground to unlock; ?

PUSH+: refers to the short-circuit positive pole unlocking, and the output of some access controllers is instantaneous 12V, which is connected to this terminal;

NC: means normally closed;

No: normally open;

COM: refers to the public terminal;

LOCK+: refers to the L+connected to the intercom terminal;

LOCK-: means L- connected to the intercom terminal.

Knowledge expansion of access control equipment;

Introduction:

Refers to the prohibition authority of "door", which is a precaution against "door". The "doors" here, in a broad sense, include all kinds of passable passages, including doors for people and vehicles. Therefore, access control includes vehicle access control. In the application of parking lot management, vehicle access control is an important means of vehicle management.

Li Daoyuan in the Northern Wei Dynasty wrote "Notes on Water Classics and Valley Water": "Cao Zijian wants to walk in the Imperial Street, which violates the access control and is humble." Song and Wu's "Dream Inside": "The access control is so strict that people dare not look up." Sheng Shuidong Diary Killing Ma Shun, etc.: "I didn't know that the access control was quite strict until I drove out."

Access control system:

The entrance guard safety management system is a new modern safety management system integrating microcomputer automatic identification technology and modern safety management measures, which involves many new technologies such as electronics, machinery, optics, computer technology, communication technology and biotechnology. It is an effective measure to solve the entrance and exit problems of important departments and realize safety management. Suitable for all kinds of security departments, such as banks, hotels, computer rooms, armories, confidential rooms, offices, intelligent communities, factories and so on.

With the rapid development of digital technology and network technology, access control technology has also developed rapidly.

It has already gone beyond simple doorways and key management, and gradually developed into a complete access control management system. It plays an important role in administrative work such as safety of working environment and attendance management.

On the basis of this system, corresponding auxiliary equipment can be added, such as elevator control, vehicle access control, property fire monitoring, public security patrol management, catering charge management, etc. And truly realize the intelligent management of the regional one-card system.

Access control system, also known as access control system, is an intelligent management system for managers to access. To sum up, it is to manage who can go in and out of which doors at what time and provide inquiry reports afterwards. Common access control systems include password access control system, contactless card access control system, fingerprint iris palm biometric access control system and face recognition access control attendance system. Access control system has developed rapidly in recent years and has been widely used in management control system.