Specifications

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13. Appendix B – Wiegand Protocol

The Wiegand protocol has become a standard means of communicating user

identification numbers between access control front-end products, such as a card

reader or keypad, and the access control system interface to that front-end.

Some manufacturers have modified the original standard format for their own use,

but often still support the original standard.

The V-Smart reader shall support a variety of formats; however, the factory default

is the Standard 26-bit format as described below. Note that the format selected

shall be used for both Wiegand input (extracting sequence from external proximity

card reader) and Wiegand output (releasing sequence to Access Control

System). The V-Smart shall not support the use of a different format for input than

output.

13.1. Standard 26-bit Format

The Wiegand protocol is described completely in a document available from

the Security Industry Association (SIA) as Access Control 26-bit Wiegand

Reader Interface Standard. Without going into the detail provided in that

document, the Wiegand communication format can be summarized as

providing a series of binary bits (0 or 1) that are interpreted as two (2) data

fields: site code and identification number. Proprietary and customized

formats are prevalent and can contain extended data ranges or additional

data fields, but the standard format is 26-bit.

The 26-bit format is generally diagrammed as follows:

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

S S S S S S S S N N N N N N N N N N N N N N N N P

E E E E E E E E E E E E O O O O O O O O O O O O

Where P represents a parity bit, S represents a bit from the Site Code (also

referred to as a Facility Code), N is a bit from the ID Number (also referred to

as Card ID), E represents bit positions that are used for Even parity

calculations, and O represents bit positions that are used for Odd parity

calculations. The facility code is 8 bits and supports values from 000 to 255.

The ID number is 16 bits and supports values from 00000 to 65535.

In the case of a V-Smart the ID number assigned to each fingerprint template

should be enrolled in the Access Control System as the Card ID.