51 Research and Design, Electronic Engineers website - Embedded Systems, MCU, DSP, EDA, Test and Measurement, Components, Communications, Power, Microelectronics, Semiconductors

Tuesday, November 24th, 2009 at 10:48 | No comments

Categories: Embedded system

Tags: microcontroller, modem

Short Content: Abstract: Introduced one kind (MODEM) the connection carries on long range data gathering and the transmission practical electric circuit take the W78E52 monolithic integrated circuit as the control core and the modem. This circuit structure is simple, the reliability is high, the control is convenient. In the article narrated the MODEM AT instruction description as well as controls MODEM with the monolithic integrated circuit the method, and unified the system function and the principle has given the master routine ...

Thursday, December 11th, 2008 at 01:29 | No comments

Categories: Communication Networks

Tags: design, modem, Power line

Short Content: Power line surfer good and bad points The power line correspondence (Power line Communication) is called "PLC", is one kind carries on the high speed data transmission using the electric transmission and the power supply power line the technology. 1 power line transmits merit The power line proliferates the city and the village, its coverage is any network is unable to compare, is advantageous in the power line correspondence (PLC) the network promotion. PLC through the power line transmission data, ...

Saturday, November 22nd, 2008 at 04:19 | No comments

Categories: Communication Networks

Tags: data transmission, modem, μC/OS-II

Short Content: The abstract introduces one kind of long range data transmission system. This system is a communications cable state of health observation system's part, it based on μC/OS-II the software platform, uses LPC2132 to control Modem chip 73M2901, realizes the data long-distance transmission through the telephone line. This plan operation reliable, the cost is low, easy to promote, may widely apply in the industry long-distance monitoring, the intelligence lives, the unattended place and so on each domain.Key word μC/OS-II LPC2132 73M2901 ...

Sunday, November 2nd, 2008 at 03:16 | No comments

Categories: DSP

Tags: DSP, hypothesized instrument, modem, software radio

Short Content: Abstract: The design has realized a set based on the software radio the software MODEM experiment system, this system hardware take TMS320C6711 digital signal processor (DSP) as a core, realizes the software radio multi-service pattern modulation demodulation function, and designs the hardware interface to complete with the main engine real-time communication. Designs the hypothesized instrument control in the main engine to demonstrate the platform, realized to modulated the demodulation service pattern the real-time choice and the measured data real time ...

Thursday, October 30th, 2008 at 04:03 | No comments

Categories: Communication Networks

Tags: asynchronous communication, modem, MSM7512B

Short Content: Introduction     The portable instrument usual use modem realizes the data long-distance transmission, is limited the condition, the portable instrument uses the modem requests to have the power loss to be low, the temperature adaptation scope wide, the exterior part are few, power supply simple and so on characteristics. This article introduces OKI the corporate design manufacture 1200 baudrate modem MSM7512B series components. This chip may through the use frequency shift keying modulation working (Frequency Shift Keyed) in a telephone ...

Tuesday, October 28th, 2008 at 11:27 | No comments

Categories: SCM

Tags: MCS-51, modem

Short Content: GPS is in the present technology is maturest, and already practical one kind of positioning system, but in GPS positioning system, because it is an unidirectional guidance system, he is and so on passes to the ephemeris data the ground receiver, may when many concrete applications, for example in the vehicles dispatching system, needs the message data which obtains using GPS to pass to generally the control center, because its system stands by a datum with many subscriber switchboards is ...

Tuesday, October 28th, 2008 at 00:57 | No comments

Categories: Communication Networks

Tags: AM7911, expansion, Is shifted, modem, MODEM the

Short Content: Introduction 　　　　Pass on equipment's development along with the microcomputer and the number, modem's transmission speed are getting higher and higher, the variety are also getting more and more.　　　　Is very narrow as a result of telephone system's bandwidth, but in numerical information's rectangular wave has the very rich harmonic content, transmits directly it in the telephone line, will create the big signal distortion inevitably in the receiving end. The use modem will simulate the carrier to modulate, then may solve questions ...

Sunday, October 26th, 2008 at 22:17 | No comments

Categories: Communication Networks

Tags: A5191HRT, HART, modem

Short Content: Abstract: First introduces A5191HRT the HART modem's principle. A5191HRT internal integrated has conformed to the Bell202 standard complete modulation demodulation electric circuit, was convenient with the microprocessor connection, is advantageous for the construction intelligence scene measuring appliance's HART agreement connection module electric circuit. Finally gives some intelligent scene measuring appliance based on A5191HRT and the AD421 electric current ring content, the mold switch's HART agreement connection module design.Key word: HART agreement; Serial communication; Frequency-shift keying; Modem 1 introduction    In the ...

Sunday, October 19th, 2008 at 03:32 | No comments

Categories: Communication Networks

Tags: CX20493, CX86500, modem, The tax controls cash register

Short Content:     The financial tax controls the cash register is "the silver tax integration" terminal product. This product is take the E-government, the electronic commerce development as a background, take Jin Shui, the gold card and so on "the gold" the character series project interaction, the fusion development as the foundation, take the resources conformity, the information sharing, the interconnection intercommunication impetus informationization development as the goal, promotes profession organic fusions, the development and so on tax affairs, bank, trade informationization ...

Wednesday, October 15th, 2008 at 08:00 | No comments

Categories: Communication Networks

Tags: modem

Short Content: 　　(Digital subscriber line) the signal is similar based on the family power line's network signal and xDSL, because two kind of signals have both used one kind of OFDM (Orthogonal Frequency Division Multiplexing) the form. Two kind of signal's application systems also need the very big output current, the very wide band width and the good linearity. This design example describes one kind of design to have the xDSL driver's simple line driver electric circuit, uses transmits the high speed ...