We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Stop Bit?

By Ken Black
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A stop bit is a character in asynchronous communication that lets a receiver know that the byte being transmitted has ended. This is vital to the way most information is transmitted over the Internet. Without a stop bit, it is possible that a receiver's computer would likely prompt an error message and make further communication with the sending computer problematic.

Asynchronous communication means that data is transmitted without any external clock. As such, a receiving computer requires knowing when the byte ends in order to get "ready" to receive the next byte. In addition to a stop bit, the other piece of the puzzle is the start bit, which signals the beginning of a new piece of information.

Information transmitted over the Internet is broken down into blocks of data, known as bytes, for transmission. Bytes normally include eight bits of data, plus a start bit and stop bit for a 10-bit character frame. These bytes are then assembled to present the data in its original context. Bytes can be parts of a computer program, or something as simple as words in an e-mail.

Curiously, while a stop and start bit are normally associated with modern technology, including state-of-the-art data transmission, the two terms have their roots in older communications technologies. For example, teletype machines in the late 19th and early 20th centuries had to be resynchronized after the start of each character, called codes. These codes could often include more than one word. However, after each code was transmitted, a stop bit would also be transmitted to indicate to the receiving team that it was time to resynchronize.

In some cases, older teletype machines may have required more than one stop bit. However, in modern asynchronous communication, no more than one stop bit is needed. This may confuse some computer users who stumble onto the Windows communications configuration panel, especially in computers with older operating systems. A myriad of choices are presented, most of which make no sense by today's data transmission standards.

If a stop bit is not present for a computer receiving data, an error message will likely come up. This error is called a framing error and may be caused by the bytes not being properly formatted. It may require the attention of an IT professional. Usually, a framing error is the fault of the sending machine, not the receiving, though it is possible signal degradation could also cause a framing error.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon43336 — On Aug 27, 2009

One voltage is a "1"; the other voltage is a "0". The two voltages, and what logic level they represent, can be anything we agree on. The various "standards" are what was agreed on.

Jim

By loaded4gig — On Feb 02, 2009

I was just wondering how a network interface card can operate with just the pos 15 and neg 15 volts for bit transmission without needing to read the 0 volt or idle voltage---can someone help me out here?-Thanks,Karl

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.