Access control tips: What is the Wiegand agreement we often talk about?

Access control tips: What is the Wiegand agreement we often talk about?

The Wiegand protocol is also known as Wiegand code, which is a communication tool in popular terms, used from the card reader (read head) to the access controller. When the card reader recognizes a valid card, it transmits the key information of the card in the Wiegand protocol, and then converts it into data and sends it to the controller. The controller opens the door after verifying that the key information is valid.

In short, the Wiegand protocol is equivalent to a “microphone”, the controller cannot directly read the information sent by the reader, so the Wiegand protocol is required for communication to complete the complete transmission of data from the reader to the controller. It is worth noting that the Wiegand protocol can only achieve one-way transmission. The information transmitted by the reader to the controller is one-way. The controller cannot send a signal to the card reader. The controller needs to use other tools to make feedback (such as LED Lights).

Wiegand interface usually consists of 3 wires, they are: DATA0, DATA1 and GND. Wiegand code only needs two data lines in data transmission, one is DATA0 (usually a green wire), and the other is DATA1 (usually a white wire).

Advantage

• Simple, versatile, low cost, and easy to connect with technology.

Disadvantage

• 1. The Wiegand protocol is a universal protocol, which is accepted by almost all access control systems. Therefore, it has low security and cannot be encrypted. It is equivalent to a plaintext code and can be copied at will.
• 2. The transmission distance is short, 100m.
• 3. One-way transmission, highly restrictive.