How To Troubleshoot Wiegand Reader Problems - Inverted Wiring

By: Brian Rhodes, Published on Jul 16, 2019

Wiegand is the dominant method of connecting access readers, but problems can arise for installers.

In fact, one of the most difficult reader installation issues to troubleshoot is caused by wiring it wrong.

However, inside we explain how to find the wiring issue using an app, making it possible to diagnose over the phone.

Strange Card Numbers Common Problem

Often, access installers will report issues such as 'All but one of the card readers installed report the correct card number. Cards work on all but that one reader!' 

A significantly confusing aspect is the cards function as expected elsewhere. The reader works as expected otherwise except for reporting strange credential numbers, seemingly unrelated to the actual number every time they are used.

Here's an example of this type of issue, captured on a social media group:

The problem often results in dispatching a technician to the site, and can lead to the (ultimately unneeded) replacement of readers and/or credentials, costing hundreds of dollars.

Below we explain how to troubleshoot the issue using Windows Calculator over the phone.

******* ** *** ******** method ** ********** ****** readers, *** ******** *** arise *** **********.

** ****, *** ** the **** ********* ****** installation ****** ** ************ is ****** ** ****** it *****.

*******, ****** ** ******* how ** **** *** wiring ***** ***** ** app, ****** ** ******** to ******** **** *** phone.

Strange **** ******* ****** *******

*****, ****** ********** **** report ****** **** ** 'All *** *** ** the **** ******* ********* report *** ******* **** number. ***** **** ** all *** **** *** reader!' 

* ************* ********* ****** is *** ***** ******** as ******** *********. *** reader ***** ** ******** otherwise ****** *** ********* strange ********** *******, ********* unrelated ** *** ****** number ***** **** **** are ****.

****'* ** ******* ** this **** ** *****, captured ** * ****** media *****:

*** ******* ***** ******* in *********** * ********** to *** ****, *** can **** ** *** (ultimately ********) *********** ** readers ***/** ***********, ******* hundreds ** *******.

***** ** ******* *** to ************ *** ***** using ******* ********** **** the *****.

[***************]

Card **** ***** ** *******

*** **** ****** *******, only ***** *********** *** used ** ******** ***********. Even *** ******** **.** MHz ***********, ***** *** only ******* ** **** on *** **** **** to ********* ***** ** called * '**** ****** number', ** ***.

**** *** ** ***** the **** ****** *******, embossed, ** ****** ** the ****. ** *******, every ****, *** ************* user, **** *** * 'unique' ******.

*** ***** ***** ***** example *** ******** ** credentials:

Problem **** *****: ******** ****** ******

*** ************ ********** ******* reader *** **** ********** must ** ***** ********* for *******, ******** ********** data ** ** ****** between *******.

*** *** ******** ** access *******, **** ********** uses *** ********* *****: generally *** '*****' *** 'white' ****** *****, ******** called *** '******* *****'. Some ********** *** ** observed ** ***** *******, but **** *** ***** readers ************ *** ***** conductors *** ******* ***********.

*** ***** ***** ***** connect ** ****** *** crucial ** ****.  ** general, ******* ***** *** connected ** *** '**' and '**' *****, *** the **** *****/******** **** be ********.

**** **********, **** *********** ones, ********** ***** *** 'D0/Green' **** ** *** 'D1' **** *** ** on, ******* * *** problem **** ** **** to ****** ** * casual ****:

Diagnosing ******* ***** ******* **********

****** **** ************ *** wiring ********, *** ******* for ******** **** ****** wiring ******* *** ** done **** * ******* PC ** **** ********/**** the ***** **** **** the ********** ******* ********** by *** ****** *** the ****** ********** ****** on *** **** ******.

*** **** **** ******* is *************** *** **** 'free' ******* **********, ******** any *********** **** ******** decimal ******* ** ****** can ** ****.

*** ***** ***** ***** Windows **********:

  1. ** * **, *********** ********** ** '**********' Mode
  2. **** ** *** ******/*** credential ***** (******* '*****')
  3. ***** *** ****** (***) value (******* '**** **** 0101 ****')
  4. ***** *** ******* ****** value ** **** ****** back **** **********. ******* all '*' **** '*' and **** *****. (******* '0101 **** **** ****')
  5. ***** *** ******* (***) value ** *** ** it ******* *** ******* credential ***** **** ******* on *** ****. (******* '23713')

** *** ******* ***** in **** * ******* the ****/ **** ****** be **** ** *** reader, *** ** *** D1 ***** *** ******** or *********** **********.

*** ******* ** ******* fixed ** ******** *** wires ** ** ** the ******* *****, ******** the **********, ********, ** termination ****** *** ******** Wiegand ******.

Video ***********

*** ***** ***** ************ the *******, ** ** use ******* ********** ** Binary **** ** ***** inverse ****** ** *** system ******* **** ***** values ****** ******** ****:

Wiegand **** ******

*** ******* ***** ****** on *******, ***** ****** binary, ** ******** ********** information ** ****** ***********.

** *******, ******* *********** use *** ***** ** communicate **** ******. **** dormant, **** ** *** two *****, ** (*****) and ** (*****) **** a **** ******* ** 5 *** ** *** line.

**** **** ** **** by *** ****** **** a ********** ** ****, the **** ******* *********** drops ** * ***. This **** ** ********** as ****** * '*' or '*' ****** ***** based ** ***** **** the **** ** ****:

****** ******* ** *********** values, ***** ******* *** either '*' ** '*' and *** *** ******* or *********. 

******* ***** ****** *** basic ******, ********** ******** up *** ***** ********** registers **** ** *** wrong ****, ***** ******* a *********** *****, *** access ****** ******* ******.

Does *** **** *** ****

** ****, *** ****** above **** *** **** for *************** **** ********* readers, **** *******.

*****~**% ** *********** ****** they *** ******* *** majority ** *** ****, *** ******* *** ********* nature ** **** ***** that ******, *********** ****** is ** ****** ****.

*************, *** **** ******* uses ****** ** **** one ** *** **** troubling ******** *****, ********** to '*** ** *** middle' ******** *** $** ****** ** ******* ******* **** **** **** details ** ********** ******* often *******$** ** ****.

Comments (5)

Undisclosed #1

07/16/19 02:58pm

Some more calculator fun.

Avatar

Brian Rhodes

IPVMU Certified | In reply to Undisclosed #1 | 07/16/19 03:14pm

Hey thanks!  That's cool.  

Basically that document explains how individual card values can be extracted from hexadecimal values using Windows Calculator. This is useful if you need to 'dissect' the records in raw user database or some other manual task.

Undisclosed #1

In reply to Brian Rhodes | 08/12/19 01:23am

Some more general nerdiness and geekwit across multiple platforms. Did not know where to plug this one since it is not the typical security industry topic however there are other connections to be made with security and hardware. Connect the dots within the box.

https://pagedout.institute/download/PagedOut_001_beta1.pdf

Undisclosed Manufacturer #2

07/18/19 02:12pm

No need to mess about with hex or binary here, nor getting the number and swapping 0s and 1s.
Simpler to subtract the number from 65535
65535-41822=23713
65535-65523=12

Obviously that doesn't explain why it is wrong, and why this fixes it.

Undisclosed Integrator #3

07/19/19 01:29pm

Its Complicated to work in HEX, normal installer doesnt have this info

Login to read this IPVM report.
Why do I need to log in?
IPVM conducts unique testing and research funded by member's payments enabling us to offer the most independent, accurate and in-depth information.

Related Reports on Access Control

The Access Control Codes Guide: IBC, NFPA 72, 80 & 101 on Nov 07, 2019
For access, there is one basic maxim: Life safety above all else. But how do you know if all applicable codes are being followed? While the...
90+ Companies Profile Directory on Nov 05, 2019
While IPVM covers the largest companies in the industry regularly (like Axis, Dahua, Hikvision, etc.), IPVM strives to do a profile post on each...
Tailgating: Access Control Tutorial on Oct 31, 2019
Nearly all access control systems are vulnerable to an easy exploit called 'tailgating'. Indeed, a friendly gesture in holding doors for others...
France Declares School Facial Recognition Illegal Due to GDPR on Oct 31, 2019
France is the latest European country to effectively prohibit facial recognition as a school access control solution, even with the consent of...
Lock Status Monitoring Tutorial on Oct 28, 2019
Just because access doors are closed does not mean they are locked. Unless access systems are using lock status monitoring, the doors and areas...
Security Canada Central Show Report 2019 on Oct 24, 2019
IPVM attended Security Canada Central in Toronto to see what is new in the Canadian market. Inside, we share videos and dozens of images...
Covert Elevator Face Recognition on Oct 24, 2019
Covert elevator facial recognition has the potential to solve the cost and complexity of elevator surveillance while engendering immense privacy...
Access Control Door Controllers Guide on Oct 22, 2019
Door controllers are at the center of physical access control systems connecting software, readers, and locks. Despite being buried inside...
Securing Access Control Installations Tutorial on Oct 17, 2019
The physical security of access control components is critical to ensuring that a facility is truly secure. Otherwise, the entire system can be...
Access Control Course Fall 2019 - Last Chance on Oct 17, 2019
Register Now - Fall 2019 Access Control Course. Thursday, October 17th is the last day to register. IPVM offers the most comprehensive access...

Most Recent Industry Reports

Hikvision Markets Uyghur Ethnicity Analytics, Now Covers Up on Nov 11, 2019
Hikvision has marketed an AI camera that automatically identifies Uyghurs, on its China website, only covering it up days ago after IPVM questioned...
Open vs End-to-End Systems: Integrator Statistics 2019 on Nov 11, 2019
Preference for open systems is on the decline, according to new IPVM statistics. We asked integrators: For video surveillance systems, do you...
Biggest Low Light Problems 2019 on Nov 08, 2019
Over 150 integrators responded to our survey question: "What are the biggest problems you face getting good low-light images?" Inside, we share...
US Issues Criminal Charges For Fraudulently Selling Hikvision And Other China Products on Nov 07, 2019
The US government has made an unprecedented move on the video surveillance supply chain, charging a US company, Aventura for "having conspired with...
The Access Control Codes Guide: IBC, NFPA 72, 80 & 101 on Nov 07, 2019
For access, there is one basic maxim: Life safety above all else. But how do you know if all applicable codes are being followed? While the...
Rhombus Cameras, VMS and Analytics Tested on Nov 06, 2019
Rhombus boasts they have created "the new standard in Enterprise, cloud-managed video security" and told IPVM in January 2019 they offer twice the...
"Stress in the Residential Market" - Major Lender Exits on Nov 06, 2019
The residential security / 'alarm' market is getting worse, at least for traditional players. Now, one of the biggest lenders in the industry has...
Aiphone Video Intercom Tested (IX Series 2) on Nov 05, 2019
Aiphone was one of integrator's favorite intercom manufacturers but how well do their products work? The company's newest offering, the IX Series 2...
90+ Companies Profile Directory on Nov 05, 2019
While IPVM covers the largest companies in the industry regularly (like Axis, Dahua, Hikvision, etc.), IPVM strives to do a profile post on each...
Hikvision USA Fights LTS on Nov 04, 2019
Hikvision's USA subsidiary is fighting with LTS, having recently quietly dropped LTS as an authorized distributor amidst ongoing face-offs between...

What IPVM Is

The world's leading authority on video surveillance, with 200,000+ visits monthly.

  • Articles on cameras, video analytics, VMS, and trends
  • Tests showing actual performance and problems
  • Courses in surveillance, access control, etc
  • Camera Calculator for designing systems

Dedicated To Independence

We're dedicated to staying independent and objective. We're the only industry source to refuse any and all advertisements, sponsorship, and consulting from manufacturers. Why?