User Rank
Re: Nov 26 - Day 1: Implementing USB in Embedded Products
RichQ   11/29/2012 8:31:32 PM
@gongji, the A and B connectors are to distinguish a host from an endpoint. The A connector plugs into a host and the B connector plugs into an endpoint. So, the cable between your PC and your printer has an A connector on the end going to the PC and a B connector going to the printer. This helps keep the signal polarities correct as well as preventing someone from trying to use the printer as a USB host.

In fact, I dont think any USB cable has the A connector on both ends. If it did, somone could really mess things up by trying to connect two hosts together.

Your flash drives have only an A connector because, in essence, the functional equivalent of the cable with its B-end is an integral part of the flash drive, so only the A end of the "cable" is actually used.

Partner Zone
Latest Analysis
Design News previews some of the solutions exhibitors that will be at the huge UBM-organized design, engineering, and manufacturing trade show in Anaheim in February 2016.
The common denominator in just about every electromechanical system is the use of a motor. If sensors will be the eyes and ears of the IoT, motors will be the arms and legs.
The IRB 8700 is aimed at material-handling applications in the automotive, transportation, and other heavy industries.
Governmental policies and mandates in Europe are leading the way in creating low-carbon manufacturing.
Digital healthcare devices and wearable electronic products need to be thoroughly tested, lest they live short, ignominious lives, an expert will tell attendees at UBM’s upcoming Designers of Things conference in San Jose, Calif.
Design News Webinar Series
11/10/2015 11:00 a.m. California / 2:00 p.m. New York
10/29/2015 11:00 a.m. California / 2:00 p.m. New York
10/20/2015 8:00 a.m. California / 11:00 a.m. New York
12/2/2015 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Jul 6 - 10, Building Raspberry Pi Controllers with Python
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service