--- title: The ABC's of Fiber Polarity description: Fluke Networks MultiFiber Pro allows you to test individual patch cords, permanent links and channels for correct polarity. image: https://www.accu-tech.com/hubfs/2017%20Redesign%20Vendor%20Banners/purely%20fiber%20mostly%20blue.jpg --- {% set baseFontFamily = "Open Sans" %} /* Add the font family you wish to use. You may need to import it above. */ {% set headerFontFamily = "Open Sans" %} /* This affects only headers on the site. Add the font family you wish to use. You may need to import it above. */ {% set textColor = "#565656" %} /* This sets the universal color of dark text on the site */ {% set pageCenter = "1100px" %} /* This sets the width of the website */ {% set headerType = "fixed" %} /* To make this a fixed header, change the value to "fixed" - otherwise, set it to "static" */ {% set lightGreyColor = "#f7f7f7" %} /* This affects all grey background sections */ {% set baseFontWeight = "normal" %} /* More than likely, you will use one of these values (higher = bolder): 300, 400, 700, 900 */ {% set headerFontWeight = "normal" %} /* For Headers; More than likely, you will use one of these values (higher = bolder): 300, 400, 700, 900 */ {% set buttonRadius = '40px' %} /* "0" for square edges, "10px" for rounded edges, "40px" for pill shape; This will change all buttons */ ### After you have updated your stylesheet, make sure you turn this module off [Click to Contact Sales](https://www.accu-tech.com/contact-us) | Call Corporate Office at [888-222-8832](tel:18882228832) [![Accu-Tech logo with tagline in navy blue](https://www.accu-tech.com/hs-fs/hubfs/Accu-Tech%20Blue%20Tagline%20300px%20-%20Edited.png?width=300&height=95&name=Accu-Tech%20Blue%20Tagline%20300px%20-%20Edited.png "Accu-Tech logo with tagline in navy blue")](https://www.accu-tech.com/) # The ABC's of Fiber Polarity by **[Teddi Strassburger](https://www.accu-tech.com/accu-insider/author/teddi-strassburger)** on October 10, 2018 Polarity defines the direction of flow, such as the direction of a magnetic field or an electrical current. In fiber optics, polarity defines the direction in which light signals travel through an optical fiber. For everything to work properly and for data to be sent correctly with light signals, a fiber optic link's transmit signal (Tx) at one end of the cable must match the corresponding receiver (Rx) at the other end of the cable. Polarity can be a confusing topic, so let's take a deeper look at how it works.  **Easy to Understand Duplex** In duplex fiber applications, such as 10 Gig, data transmission is bidirectional over two fibers - each fiber connects to the transmitter on one end and to the receiver on the other end. Polarity ensures this connection is maintained.  TIA-568-C standards recommend an A-B polarity scenario for duplex patch cords. In this scenario, the Tx (B) should always connect to the Rx (A), regardless of how many patch panel adapters or cable segments are in the channel. The A-B duplex patch cord is a straight-through connection that maintains the A-B polarity in a duplex channel.  **More Complex Multiples** Multi-fiber MPO type cables and connectors can add more variables to the mix. Industry standards have identified three polarity methods for MPOs - Method A, Method B and Method C. Each method uses different types of MPO cables. ![Type-A](https://www.accu-tech.com/hs-fs/hubfs/2017%20Redesign%20Vendor%20Banners/Type-A.png?width=1000&name=Type-A.png) Method A uses Type A straight-through MPO trunk cables with a key up connector on one end and a key down connector on the other end. Method B uses key up connectors on both ends to achieve the transceiver-receiver flip. Method C is very similar to Method A, but each pair of fibers is flipped.  With three different polarity methods and the need to use the correct type of patch cords for each, deployment mistakes can be common. The Fluke Networks MultiFiber™ Pro allows you to test individual patch cords, permanent links and channels for correct polarity.  [Click here to learn more about Fluke Networks.](https://www.accu-tech.com/more-vendors/fluke-networks) [Click here to contact your local Accu-Tech representative. ](https://www.accu-tech.com/contact) - [Tweet](https://twitter.com/share) Topics: [Fluke Networks](https://www.accu-tech.com/accu-insider/topic/fluke-networks) [fluke](https://www.accu-tech.com/accu-insider/topic/fluke) [polarity](https://www.accu-tech.com/accu-insider/topic/polarity) [fiber polarity](https://www.accu-tech.com/accu-insider/topic/fiber-polarity) ### Subscribe To Our Blog ### Additional Information ### About Accu-Tech Accu-Tech is a national distributor of Voice, Data, AV, Wireless, and Security solutions. We partner with best-in-class manufacturers to provide the integrated, future-proof solutions our customers require. From project services and management to on-the-job-site logistics, Accu-Tech ensures every customer’s project is supported from design to completion. With 35 stocking locations strategically placed nationwide, Accu-Tech is readily available to assist when and where you need us. [Terms of Sale](https://www.accu-tech.com/termsandconditions) | [Terms of Use](https://www.accu-tech.com/termsofuse) | [Privacy Policy](https://www.accu-tech.com/privacypolicy)     ### Recent Posts ### [Contact Us ](https://cta-service-cms2.hubspot.com/web-interactives/public/v1/track/click?encryptedPayload=AVxigLLgoNM15ESCtUItoORUnIpVEza%2FXxPjeQo6xlTR%2Fj4WhU19s%2BVGyVX5EAmm5U0akqy%2BbMhqy4pXrnN8BEH06Bl%2BRyWz8C3Fe6IQoP4s8tBL9ZKgptuib%2FiXcs%2BLgLo2svy%2FE9IIS7NKZ1d7SwPB0KTFqrNKfOB7feelc1N9E3omjvx2%2FrB7Ug%3D%3D&portalId=54495) TOLL-FREE: 888-222-8832 [www.accu-tech.com/contact](https://www.accu-tech.com/contact) ### Follow us on social media:  | [![Facebook_Logo_Secondary-1](https://www.accu-tech.com/hs-fs/hubfs/Facebook_Logo_Secondary-1.png?width=162&height=162&name=Facebook_Logo_Secondary-1.png)](https://www.facebook.com/accutech/)   | [![X_logo_2023_(white)](https://www.accu-tech.com/hs-fs/hubfs/X_logo_2023_(white).png?width=58&height=58&name=X_logo_2023_(white).png)](https://twitter.com/Accu_Tech)   | [![In-White-96@2x](https://www.accu-tech.com/hs-fs/hubfs/In-White-96@2x.png?width=50&height=50&name=In-White-96@2x.png)](https://www.linkedin.com/company/accu-tech-corporation)   | [![youtube-app-white-icon (1)](https://www.accu-tech.com/hs-fs/hubfs/youtube-app-white-icon%20(1).webp?width=58&height=58&name=youtube-app-white-icon%20(1).webp)](https://www.youtube.com/user/AccuTechCorp)   | | --- | --- | --- | --- |