Serial Bus

Serial BusJohnlee P. MendozaBsit-121

HistoryIEEE Std 1394-1995 (also known as FireWire or i.Link), developed byT10

https://en.wikipedia.org/wiki/Serial_Bus_Protocol_2

Objectives

Explain Serial BusShow the RS 232 modem applicationAdvantage and Disadvantage of Serial Bus

DefinitionSerial BusBit by bit transmission of information in series

http://web.calstatela.edu/faculty/nganesa/College%20Courses/Slide%20Download%20Pool/Communication%20Theory/Serial%20and%20Parallel%20Communication.ppt

Series1.0 diagram of Serial Bus

IntroductionSerial buses, is a compound word consisting of a serial and a busesserial mean sequential, in order , or one-by-one. bus(singular for buses) is derived from latin word omnibus meaning for all. So literally serial buses mean one-by one for all.Serial communication

http://www.slideshare.net/umargaro/serial-buses

2.0 Image of Serial Communication Bus Connecting peripheral to Computer

types of serial communications:RS232. RS422. RS485.USB (Universal Serial Bus)

http://cse.spsu.edu/qian/resource/Ch6-ppt.ppt

Advantage and Disadvantageof Serial Bus

AdvantagesLess CostTo control the effect of electromagnetic interference from the environmentTo allow full duplex communication with no loss of data


DisadvantageLower speedDifficult to maintain data integrity due to problems with synchronizing clocks

http://www.engr.sjsu.edu/wdu/ME296N/2006/Lecture/Lecture8_SerialParalle.pdf

Types of Serial Bus

RS232(Standard 232)Commonly used for one to one communication.1 Receiver onlySerial binary single-ended data and control signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data Communication Equipment).


1.1 Diagram showing DTE and DCE equipment

History Rs-232It was originally established in 19621969. (RS-232-C) was to be accepted as a standard for computer manufacturers.1987. EIA association elaborated a new version of the standard which was called EIA-232-D.1991. EIA together with Telecommunications Industry association (TIA) elaborated a new version of the standard which was called EIA/TIA-232-Ehttp://www.lookrs232.com/rs232/history_rs232.htm

RS-232 Parametersends the data character by character

This mode of communication is called asynchronous communication


What is Asynchronous?usually used to describecommunicationin whichdata can be transmitted intermittently rather than in a steady stream.SenderStopDataStartReceiver1,2 Diagram of Asynchronous

RS-232 Connectors25-pin connector and 9-pin connector50 feet can be extended to several hundred feet with high-quality cable


1.3 Db-25 pins connector diagram

1.4 Db-9 pins connector diagram

1.5 Specification of Rs-232

RS-422one of the fastest serial data rates at 10Mbps. up to 10 receiverscannot be used to construct a truly multi-point network.

1.6 Master and 1-slaves transceiver diagram

1.7 Master and 4-slaves diagram

1.8 Specification of Rs-422

1.9 Rs-232 can be converted into Rs-422

(RS-485)Multi-Point Communications

Similar to Rs422(more nodes per line)

Standard Specifies up to 32drivers and 32 receivers on 2 wire

2.0 Rs-485 Specification

Universal Serial Bus(USB)Communication between devices and host controllerCan connect computer peripherals such as mouse,keyboard,digital camera,cellphones etc.not need a power source of their own.


USB HistoryDevelopment in 1994Co-invented by Ajay Bhatt of Intel and the USB-IF (USB Implementers Forum, Inc.)

2.1 Diagram of USB Speed

USB Data TransferEach transfer uses a defined format to send data, addressing information, error detecting bits, and status and control informationUSB communication(with one exception in USB 3.0)supports four transfer types: control, bulk, interrupt, and isochronous


Control transferthe host sends a defined request to the device.host uses control transfers to request a series of data structures called descriptors from the deviceThree stages: Setup, Data (optional), and Status


Control TransferSetup -stage contains the request.Data stage- data from the host or deviceStatus stage- information about the success of the transfer


Bulk Transferfastest on an otherwise idle bus but have no guaranteed timingPrinters and USB virtual COM-port


Interrupt transfers

Isochronous transfers

Application

RS232 IN MODEM APPLICATIONS

Modem ApplicationMost popular uses for the RS232 standardCommunication between the two modems is accomplished via telecommunication.

http://ecee.colorado.edu/~mcclurel/dan83.pdf

2.2 Modem Communication between two PCs

Summary

SummaryAll four of these standards were written by the EIA (Electronics Industry Association) to allow peripherals and computers to communicate with each other regardless of manufacturer.

http://www.synchrotech.com/support/serial_standards.html

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Documents

Serial Bus