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D0wn و D1rty با Wiegand

چند ماه پیش، ما منتشر شده است history of where Weigand came from and a “light-on-technical-details” overview of how it works.  For those of us that are more engineer-y, it left a bit to be desired.  For me in particular, I recently was doing some low level work with one of my engineers.  We were monitoring the lines from a badge reader and I couldn’t recall what the spec for the pulse width should be.  For most people, this level of detail is overkill, but since for those of you who get down and dirty with D0/D1 of Wiegand, this post is for you.

As you might recall from our earlier post, Wiegand is used interchangeably to describe a number of things – an electronic effect, an access card, a bit stream

ویگان
Wiegand - رابط کاربری قابل اعتماد در جزئیات در این پست توضیح داده شده است.

associated with a card, or a specific reader-to-card interface.  We are going to be referring to Wiegand as the signal that comes from an access control reader, out of the Data 0 (D0) and Data 1 (D1) lines.  This data is interpreted as an access card number by parsing the bit stream.

استاندارد Wiegand تنها یک استاندارد واقعی است، اما یک وجود دارد انجمن صنعت امنیتی (SIA) document “پروتکل استاندارد کنترل دسترسی برای 26-bit Wiegand (tm) رابط خواننده” which describes an agreed standard that should work with all manufacturers’ panels.  Some of the basic information found in this document is found below.

When a reader with a Wiegand interface is hooked up to an access panel, it generally includes 6 lines with the below color scheme,  which interfaces with the back end access panel.

سیم کشی Wiegand
خروجی های D0 (سبز) و D1 (سفید) تقریبا همه خوانندگان Wiegand رنگ هستند.

Back when Telaeris was developing our XPressProx mobile proximity reader to read HID Prox cards, we needed to demodulate the data directly from the RF signal (*).  Once we decoded this signal, the data was pushed both over a USB connection as well driving the signal as over standard D0/D1 Wiegand lines.  When we hooked up our Agilent 54622D Oscilloscope to the data lines and presented different cards to the reader, these are examples of what we saw:

26bit
خروجی بیت 26
بیت خروجی 26 10000000100000010111001011 
   تقریبا حتی 1            همسایگی 1 عجیب 
                00000001 Facility = 1    
          BadgeID = 741 0000001011100101 
36bit
خروجی بیت 36
 بیت خروجی 36 011011001011001000100101101011100101 
37bit
خروجی بیت 37
بیت خروجی 37 0001001000000011111101000001011001000

The 26 bit card is parsed out for you to see as the bit format is almost universally standard.  The 36 and 37 bit cards are part of HID’s corporate 1000 line, which often mix up the location of the bits in weird and wonderful ways. The security in these cards is often simply that it is difficult to know how a bit stream might be parsed.  These bitstreams can come in a variety of lengths, all the way up to 200 for some US Government PIV cards.

 

اگر شما علاقه مند به آنچه در سطح RF برای کارت های پروکسی HID در حال انجام است، به من یک ایمیل ارسال کنید.

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  1. I am adding a cheap Ebay magnetic door access entry /magnetic door lock to my store (not for heavy security-just temp use) . I am using a Uhpotte branded stainless steel door entry keypad with Wiegand capability for programmable key fobs. There are many wires running all over my store (coming from the back of the keypad and I am stuck and my instruction manual (and everything else I find online) only shows the two wires coming out as D0/green and D1/white….and it does not instruct me where these wires go. The keypad can read cards and I imagine they connect to my control box. My options are -Control, +Control, Push, Gnd, +12v, Com, NC, NO . Of course I’m a noob and this is my first encounter with one of these. it’s been a lot of fun hooking up bbut I am ready to move forward with these last two wires. Any help you could offer would be truly appreciated. Thanks and thanks for the great article.

  2. Hello Rand – We’re not familiar with your control box. Generally, access control panels have Wiegand data ports nicely labeled and the access data can be set up from access control software. Good luck! David

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