Compatible For All Controllers
To ensure compatibility across all brands of controllers, Readers Manufacturer designed their Reader based on accepted protocol. These protocols control the communication between the readers and the controllers, enabling readers to be easily connected to any brand of controller.
There are two accepted communication protocols. They are the
Wiegand Readers are readers that comply with the Wiegand communication protocol standards agreed upon by manufacturers of Access Controllers and Readers. This ensures that the readers can be connected to the Controllers and is compatible with their systems. Wiegand Interface uses three wires, one of which is a common ground and two of which are data transmission wires usually called Data 0 and Data 1. The maximum cable run between the reader to the controller is 150m.
The original Wiegand Card format had 1 parity bit, 8 facility code bit, 16 bits for ID code, and a trailing bit making a total of 16 bits. However many access control manufacturers were unhappy with the limitation of only 8 bits for facility code and they have designed their formats with varying complexity of field numbers and lengths and parity checking.
So it is important to match the card to the reader format. For example, the Proximity Cards from HID is proprietary to HID and can only be read by HID Readers. The HID Readers themselves however can be connected to many brands of Controllers.
RS485 Readers are fast replacing the traditional Wiegand readers. RS485 is the most versatile communication standard defined by EIA and are more secure than Wiegand Readers.
The RS485 protocol is bi-directional, meaning the controller is not just listening for card readers but is in constant communication with the card reader. This removes the ability of hackers to simply replay a data stream to gain access and any means to interfere with the reader cabling will be detected within seconds. Data encryption is also possible for high-security sites as a bi-directional communication protocol.
From an installation point of view, using the RS-485 reader can lead to significant savings for larger projects. Multiple readers can sit on the same communication bus and the cable runs can be up to 900m compared to the 150m with Wiegand. We carry both types of readers as well as controllers that are compatible with both formats. Contact us for more information.