Format and Facility (Site) Code explained
Definition of "Format"
A proximity card stores data. A "format" is the structure of the binary data stored in the card. The number of ones and zeros, and how they are put together, determines the format and ultimately the credential number. When a card is waved in front of a reader, those numbers are sent to the access controller. However, the controller needs to know how the received information is organized., i.e. the format.
For example, if we see a string of numbers, 9395981699, it may mean nothing to us. But, if we know it s a USA phone number, then it is immediately understood that 939 is the area code, and the rest of the numbers, the phone number. Then, knowledge of the format allows to properly decode the data.
The 26 bit Wiegand standard 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 of the higher bit formats are "proprietary", and usually carry a higher price tag. One exception is the HID 37 bit proprietary format, priced similarly to a 26 bit card.
Definition of Facility code and serial
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 two companies share the same card numbers? They could acccess each other premises.
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.
As an example, if Company A 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
Company B 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, an access control system validates the facility code AND the serial number. Company A will reject Company B cards, and viceversa, 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.
Cards ship with a facility code (if used) and serial number programmed.
How can I find my
format and facility code?
If you can read the hex format of a card, the Card Calculator may help.
For a fee (refundable in your card purchase), we can do the job of finding the programming specs for you.
Your will need to take a 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. For security reasons, we will provide this info only to established companies and institutions. We are unable to answer requests coming from free email (Yahoo!, Hotmail, Gmail...) addresses.
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)
If your installation is new, we can help you to
select the format and facility code for you.