Drain Wire For Access Control Reader Tutorial

Published Sep 23, 2020 15:05 PM

An easy-to-miss cabling specification plays a key role in access control, yet it is commonly ignored. The drain wire offers protection for readers and controllers, ensuring proper cable performance.

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We examine the drain wire, the role it plays, and why it should not be ignored.

This tutorial covers:

  • Why the drain wire is needed
  • How to identify the drain wire
  • Why access readers make them mandatory
  • Why only one end is connected
  • How much drain wires typically cost

Drain Wire Purpose

The data exchange between reader and controller can be corrupted, subject to environmental interference from other sources or even building materials like steel studs and door frames.

Given that reader wire typically is run to devices installed outside buildings, but connected to controllers deep inside them, the length of cable connecting them can attract and trap potentially degrading electrical/ EM interference that corrupts analog Wiegand or RS-485 signals between devices.

Unless the conduit between reader and controller, or controller to head end is shielded, low-level problems are difficult to diagnose and troubles can result.

OSDP *** ** ***** *****

*** **** ****** **** ** *** reader *** *** ********** ******* *** drain ****'* **********. *** ****** ******* or **-*** ******, *** ***** **** is ********. ** ** **** ********* for ******* ****.

****'* ******* ****** ** **** ******** of *** ************ **** *** **** Wiegand **********. *******, ******* **** **** readers *** ******** ** ******* ** RS-485 ***** ** ****, ************ ************ often ******* ***** * ***** **** drain **** ** ****.

*** **** ******** ** ******* ********* use *******, *** ** *** ******* adoption ** **** *********, *** ******** use ** *** ***** *** ****** less *********.

Identifying ***** ****

*** ***** **** ** ** ********** copper-tin ********* **** ** ******* ** jacketed *******. ** *** ***** *****, the ***** **** ** ********* ** it ********* ** ******** ** *** bundles.

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*********** *** ***** **** ******** * convenient ****** ** ****** ***** *********, although *** **** ****** ******** ********** from ***** ********* ************ (***) *** helps ****** *** ******** **** *** cable.

Shielding Is *** *********

*** ***** **** ** ********* ********* to *********. ***********, *** **** ** '**********' to * ***** ***, *** ******** cable **** *** *** ****** ********* when **** * ******** **** ****** is *********.

** **** *****, *** ***** ***** also ******* * ***** **** *** the ******* ** ********* *** ****** shield. *** **** *** ***-******** *****, a ***** **** ***** *** ** specified ** ***** ** ****** *** cable.

*** **** ** *********, ***** ***:********* *** ******* *** ***** ********************.

Specified **********

***** ***** **** ** ********* ********** when ******** ******** ** **** *** not ****** ******** ** ******** *******. Even ** *** ****** ****** *******, drain ***** *** *** ****** ******** (See *** ******:*** ** *** *** ************).

Access ******* ********* ******* *****

***** * '**** *****' *************, ***** wires *** ********* ******** ** *** devices **** **** *******, **** ***********, and ***** ******* ***** **** ** exchanged. * ***** **** ** ******** included ** *** ******* ******** ** readers, *** *** *** ** **** wire ** ******** ** ************:

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******* *** ********** ** *** ****** appreciated, ***** **** ************** *** ******** overlooked. ** * ******, **** ***** shielding ** *********, ** ********** ** installed **********. *** ****** ******** ** a **** ****** ** ***** ****** a ****** **** *** ****** *** cable ******* *** ************ ****** ** is ******** ********.

One **** *** *********

*** **** ****** ******** ***** **** working **** *** ***** **** ** "Which *** ** *** **** ** grounded, ** *** **** **** *********?"

***** *************, ***** ** ** ********** answer. *****, ** **** ******* ******** from ************ *******, **** **** ************* even ******** *********** ******* ******:

IPVM Image

*** ******** ***** ********** * ****** of *******:

  • *** #*: ********** *** ***** **** ** both **** ** *** ***
  • **** #* & *** #*: ********* ** *** ******
  • ****** #*: ********* ** *** **********
  • **** #*: *********** ***** ****, **** **** drain ****** ** ********

** ***** ** ** *********, *** drain ****** ** ******** ** *** end ** ***** ********* ******* ** 'drain' **** **** *** *********. *** more ** ********** *********, ************ *** ******* *** ***** ************.

*******, *** *** ************ **** *** one *** ** ** **** ** the ******. ******, **** ******* *** designed **** ******** ********** ** *** board ** ** *** ******'* ******* and ******** **** **** ** ** connected.

Added ***** ****

**** ***** ** *******, ********* ***** wire **** * ****** ****. ********* on *** ************ ****** *************, *** price ********* ******* **% ** **% per **** ****** **********/** ***** **** products. *** ****, **** ********* **** about $** ** *** ******* *****.

***** *** *** **** ********, *** including ** ********** *** ***** **** to **** *** ****** ** ******* long-term ***** ** ****** *************** *** unreliable *******.

Comments (13)
UM
Undisclosed Manufacturer #1
Sep 23, 2020

***! *** ********* ** *** ***** wire ********** *** **** ***** ** for **+ *****. * *** ****** to ****** ** *** ***** *** float ** *** ******. *** *****, the ********** ** ***** *************. * find ** **** ** ******* **** science ** *** ********** ********* (** pun ********).

(7)
(2)
UI
Undisclosed Integrator #2
Sep 23, 2020

******* *** **** ******** *** *** solve ** ******* **** ***** **** up ** * ******** ******** ******... I ***'* **** *** *** **** intermittent ** **** *******, *******, ***. I ***** ** ********** **** ****** wire.

* ****** ****** ** *** *****, because *** ** *** ***** ** was ******* ****** ** **** * good ******** ** ****** ** **** was ***** **.

(2)
(6)
UM
Undisclosed Manufacturer #3
Sep 25, 2020

**** ****** **** * ********** ***** a ******* ***** **** ** ******** damage ** ******** ******* ** **** that *** ***** ** ****** ********* strikes? ** ** **** *** *** proper ******** *** ** *******.

UI
Undisclosed Integrator #2
Sep 25, 2020

**** *** **** ** **** ****** a *****/*** ******* **** * ***'* believe * ***** **** **** ***. Put ***** ********** ** **** **** and *** ** **** *****. ** anything **** ******* ***** ** **** facility? ** ** **** ***'* *** in * ******* ***? ** ** just *** ** * **** ** does ** **** *** *** ****** and **** ***** ******* ***?

(2)
UM
Undisclosed Manufacturer #3
Sep 25, 2020

******!

****** *** **** ****. ** ***** gear *** *******, **** * *** PTZs *** *** ********* ****'* *** the ******** **** **** **, *** nearby.

*** ***** **** ***/** *****-*-* *** surge, *** ** **** ***** ******* the *** *-****** *** ******* **.

** *** ********* ************ ***** ********* like ***** *** ********* **** *** a *** ** ************ ********?

***** ***** ********** - ***-*******

UI
Undisclosed Integrator #2
Sep 28, 2020

********, *** ***** *** ** ** put ***** ** *****, **** ** have ****** **** ** *** **** is ******* *** ***** ** *** pole *** ***** ** ** *****, and *** ***** *********** ******* **** more ******* ********** ****** ** *** inside. ******** * **** **** ***** suppressors ** **** ****, *** **** have ** ****** ****** ********* ** the ****** ****. ***** ****** ** to ** **** *****, ** **** current **** ***** ******** ********? *** a ***** ********** ** ****, ****** built ** ** *********, *** **** that ***** ******** ********, *** **** that ***** ********** ** ******* **** surge **** **** *** ***********, *** to * ******.

(1)
(1)
SW
Stuart Wightman
Oct 17, 2020

**** ** *** ***** *** **** what * ********** ***** ********* *** grounding *** **** ****** ***** ** grounding ** *** ********** ****.

** ******* ** **** ** *** ground ** *** ********* ********* *** introduce *** **** ** ******* ********* being ********** ******* ********** **** *** shield ***** ***** **** *** **** of *********** ************ **** *** **** link ******* *** ********** *** ******.

** ** *** ****** **** ** the **********, *********** ***** ** *** form ** ******* ********* ***** ** a ***-***** ** ***** ***'* * circuit ******* **** **** *** *** is ******** *** *** ******** *** is ********. *** *** **** ** interference ***** **** ** ****** ****** ground ********* *** * *****.

********* *** ***** ** **** **** would ****** ********* * ******* ********* as **** **** ***** ****** ** grounded ** * ****** ********* ********* and ********* ***** **** ****** ******* the *** **** ** *** ***** by ***** ** **********. ** **** scenario ***** ** * ******* ******* from *** *** ** *** ***** wire ** *** ******** *** *** then **** ****** *** **** ** the ***** ***. **** ******* * path *** ******* ******* ** *** to **** ******* *** ******* ****** than * ***** ** ******.

*** ******* ** *** **** ****** the ***** ** *** ****** **** could ** ********** ****** ****** ******* at ********* ********* ** **** *** cause ******* ******* **** *** *** up ******** *****. ** ****** ******* at * ***** ** ********* ********* is **** ********. *** ** ***** there ** ** ****** **** ******* the *** **** ****** * **** for ***** ** ****.

** ** *** *** *** ***** to **** **** ** ** **** all *** ****** ***** *** **** ground ******** *** *** ********* ** each ***** ** **** **** *** drain ******. *** **** ******* ** the ******** ***** *** ** *** drains ****. ********* ** ***** *** same ****** ******* *** ******, ******* and ***********, *** ******* ******* ** simply ******* ** ****** *** **** not ****** * ******* ******* *** ground (*********).

** ** *** *** ***** ** a ****** **** **** ********, ** the **** ** ** **** *** shield *** **** ****** ** ******** noise *** *********** **.

** ******* ***** ****** ****** ***** me. **** ** **** *** *** I ********** ******.

(1)
Avatar
Ng Choy Mei
Oct 19, 2020
IPVMU Certified

***** **** ** **** ********* *** essential ** ***** **** ******.

TT
Tom Taylor
Oct 19, 2020
IPVMU Certified

**********... * ******* ******* ****** ******* and ************. **** ** *** ******?

JP
John Price
Jan 30, 2021

**** ********* *** ***** **** ** the ********** ** ** ****** ** tie ** ******** **** *** **(-) port *** *** **** ****** ** should *** ***** **** ** ******** at * ********* ******** ** *** controller?

Avatar
Ricardo Souza
Oct 17, 2021
Motorola Solutions • IPVMU Certified

***** *****,

***** ** * ****** **** ** "(See *** ******: *** ** *** for ************)."***** ***** ** "****" *** **** ********* ** "****"

***** ***** ** ** * ****** link ** ** **** ***** * page **** *** ********* *******:"**** ****** has *** **** *********. ***** **** later."

** * ** *** ******** *** correct **** **:*** ** *** *** ***** ************ Tutorial

=)

JH
John Honovich
Oct 17, 2021
IPVM

*******, ******! * ***** **.

(1)
SS
Samer Shehadeh
Jul 27, 2023

**** ***** ********** *** ******** (*****) cable ** *** ****** ** *** reader *** ********** ***?