Format and Facility (Site) Code explained
Format
A proximity card uses binary bits (0's and 1's) to store information.
When a card is presented to a reader, a string of numbers is sent to the access controller. But, the controller needs to know the format to understand the information received.
For example, a string of numbers, 9495981699, may mean nothing to you. But, if you know it as a phone number in the United States, then it is immediately understood that 949 is the area code, etc. Then, you can easilty understand how knowledge of the format allows to decode the data.
The 26 bit Wiegand open format is the industry standard. Card manufacturers such
as HID, Indala and AWID sell cards with this format to any dealer. This 26 bit format is recognized by all access hardware. Over the years, formats with a higher number of bits (33, 37, 48, 50) have been added to increase card security.
However, some formats are "proprietary".Those cards are sold by the card manufacturer only to the format owner, who in turn
resells the cards to the security dealers. Because of this, they are higher priced, even
if it is the same card.
For example, the HID Proxcard II card programmed with a 26 bit open format (that
we buy from HID directly) is $1.80 each. The same HID Proxcard II, with a
Kantech 26 bit propietary format (sole sourced by Kantech), is priced at $5.99
each. One exception is the HID 37 bit propietary format, sold directly by HID at the same price as 26 bit. Technical information
links:
Facility code and serial
number
Every card has a consecutive serial number
programmed, assigned in your access control software to a card holder. For 26
bit cards, it can be from 0 to 65,535.
But, what happens if a company across the street also has an access system, and
their card numbers are duplicated with yours? They could acccess your building
and viceversa.
To reduce this risk, a second number, know as the
facility or site code is encoded into
each card. This number can go from 0 to 255 on a 26 bit format card.
Then, if your company has cards numbered from 1 to 1000, with facility code 230,
they would be programmed as follows:
230 - 00001
230 - 00002
230 - 00003 .......up to 230 - 01000
The other company could have the same serial numbers, but with facility code
180, and their cards would be:
180 - 00001
180 - 00002
180 - 00003........up to 180 - 01000
To grant access, your system validates the facility code AND the serial number.
It will rejecting the other company's cards, even if they have the same serial
number, because the facility code does not match.
Lately, some formats have a greater number of bits, and make obsolete the notion
of facility codes, because the card serial number (like the serial number on
currency bills) is never duplicated at the factory. This also means faster
delivery of cards, even for add-ons to existing sites, right out of stock.
How can I find my
format and facility code?
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If you are currently using
cards, and just need to reorder, take one working sample and e-mail us the
small numbers printed near the edge (see example at right for an HID
ProxCard II card). We will use this info to check the HID database and
locate the format and facility code for you. |
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Also, you can e-mail us the
information printed on the label of one of the boxes where you received your
last batch of cards (see example at right) |
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If your installation is new, we can help you to
select the format and facility code for you.
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