Embeded-Systems. Chap14. Jitter. Jitter can be quantified in the same terms as all time-varying signals, e.g., root mean square (RMS), or peak-to-peak displacement.
Also like other time-varying signals, jitter can be expressed in terms of spectral density (frequency content). Jitter period is the interval between two times of maximum effect (or minimum effect) of a signal characteristic that varies regularly with time. Jitter frequency, the more commonly quoted figure, is its inverse. ITU-T G.810 classifies jitter frequencies below 10 Hz as wander and frequencies at or above 10 Hz as jitter. Jitter may be caused by electromagnetic interference (EMI) and crosstalk with carriers of other signals.
Sampling jitter In analog to digital and digital to analog conversion of signals, the sampling is normally assumed to be periodic with a fixed period—the time between every two samples is the same.
Avionics-Protocols. Control-Systems. EIA : Electronic Industries Alliance. Solid state relay. A solid-state relay (SSR) is an electronic switching device that switches states when an external voltage is applied along its n-type and p-type junctions.
SSR has a small control signal that controls a larger load current or voltage. It consists of a sensor which responds to an appropriate input (control signal), a solid-state electronic switching device which switches power to the load circuitry, and some coupling mechanism to enable the control signal to activate this switch without mechanical parts. The relay may be designed to switch either AC or DC to the load. It serves the same function as an electromechanical relay, but has no moving parts. Solid-state relays are composed of semiconductor materials, including thyristors and transistors.
Coupling The control signal must be coupled to the controlled circuit in a way which isolates the two circuits electrically. Many SSRs use optical coupling. Opto-isolator. Schematic diagram of an opto-isolator showing source of light (LED) on the left, dielectric barrier in the center, and sensor (phototransistor) on the right. [note 1] In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and voltage transients with speeds up to 10 kV/μs. History The value of optically coupling a solid state light emitter to a semiconductor detector for the purpose of electrical isolation was recognized in 1963 by Akmenkalns,et al.
Current mode logic. Current-mode logic is also an alternate name for Emitter-coupled logic.
Current mode logic (CML), or source-coupled logic (SCL), is a differential digital logic family intended to transmit data at speeds between 312.5 Mbit/s and 3.125 Gbit/s across standard printed circuit boards. CML termination scheme The transmission is point-to-point, unidirectional, and is usually terminated at the destination with 50 Ω resistors to Vcc on both differential lines. CML is frequently used in interfaces to fiber optic components.
CML signals have also been found useful for connections between modules. Differential signaling. Elimination of noise by using differential signaling.
Advantages Tolerance of ground offsets In a system with a differential receiver, desired signals add and noise is subtracted away. PCI Express. PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed serial computer expansion bus standard designed to replace the older PCI, PCI-X, and AGP bus standards.
PCIe has numerous improvements over the aforementioned bus standards, including higher maximum system bus throughput, lower I/O pin count and smaller physical footprint, better performance-scaling for bus devices, a more detailed error detection and reporting mechanism (Advanced Error Reporting (AER)), and native hot-plug functionality. More recent revisions of the PCIe standard support hardware I/O virtualization. The PCIe electrical interface is also used in a variety of other standards, most notably ExpressCard, a laptop expansion card interface. Cyclic redundancy check. A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data.
Blocks of data entering these systems get a short check value attached, based on the remainder of a polynomial division of their contents; on retrieval the calculation is repeated, and corrective action can be taken against presumed data corruption if the check values do not match. The CRC was invented by W. Wesley Peterson in 1961; the 32-bit CRC function of Ethernet and many other standards is the work of several researchers and was published during 1975. Introduction CRCs are based on the theory of cyclic error-correcting codes. Snubber Circuit Design Calculators.
Snubber Circuit Design Calculators See our other Electronics Calculators.
Driving inductive loads with transistor switches, whether they be flyback transformers, relays or motors often result in the high voltage resonant spikes when the coils are interrupted from their current current source by the transistor. There are various ways of mitigating these undesirable spikes which cause component failures and EMI issues. The most common approach is to use snubber circuits.
Instructive-Reading. Baud. Where fs is the symbol rate.
There is also a chance of miscommunication which leads to ambiguity. A simple example: A baud of 1 kBd = 1,000 Bd is synonymous to a symbol rate of 1,000 symbols per second. In case of a modem, this corresponds to 1,000 tones per second, and in case of a line code, this corresponds to 1,000 pulses per second. The symbol duration time is 1/1,000 second = 1 millisecond. In digital systems (i.e., using discrete/discontinuous values) with binary code, 1 Bd = 1 bit/s.
The baud unit is named after Émile Baudot, the inventor of the Baudot code for telegraphy, and is represented in accordance with the rules for SI units. Relationship to gross bit rate The symbol rate is related to but should not be confused with gross bit rate expressed in bit/s. If N bits are conveyed per symbol, and the gross bit rate is R, inclusive of channel coding overhead, the symbol rate fs can be calculated as In that case M=2N different symbols are used. FOMIS_Datasheet_WEB.pdf (application/pdf Object) FADEC. JPEG. Continuously varied JPEG compression (between Q=100 and Q=1) for an abdominalCT scan.
In computing, JPEG (/ˈdʒeɪpɛɡ/ JAY-peg) (seen most often with the .jpg extension) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Ownersmanual.pdf (application/pdf Object)
Low-voltage differential signaling. Low-voltage differential signaling, or LVDS, also known as TIA/EIA-644, is a technical standard that specifies electrical characteristics of a differential, serial communication protocol.
LVDS operates at low power and can run at very high speeds using inexpensive twisted-pair copper cables. Since LVDS is a physical layer specification only, many data communication standards and applications use it but then add a data link layer as defined in the OSI model on top of it. LVDS was introduced in 1994, and has become popular in products such as LCD-TVs, automotive infotainment systems, industrial cameras and machine vision, notebook and tablet computers, and communications systems. The typical applications are high-speed video, graphics, video camera data transfers, and general purpose computer buses.
Basic LVDS circuit operation showing current flowing in a loop back to the driver and the resulting lower radiated emission (lower EMI) due to field coupling within the differential pair. Universal asynchronous receiver/transmitter. A universal asynchronous receiver/transmitter, abbreviated UART /ˈjuːɑrt/, is a piece of computer hardware that translates data between parallel and serial forms. UARTs are commonly used in conjunction with communication standards such as EIA, RS-232, RS-422 or RS-485. The universal designation indicates that the data format and transmission speeds are configurable. The electric signaling levels and methods (such as differential signaling etc.) are handled by a driver circuit external to the UART.
Programing. Free Symbolic Computing Interactive Kit Offer - Symbolic Math DESC. Symbolic Math Toolbox enables you to find analytical solutions to your technical problems by applying fundamental math, engineering, and scientific principles. Whether you are developing algorithms, modeling engineering systems, or teaching or learning mathematical concepts, symbolic computing can offer advantages in both efficiency and transparency of solutions when compared with purely numeric approaches. Complete this form for technical resources that show how you can manage your symbolic computations in the toolbox’s notebook interface, and how symbolic results can be integrated with MATLAB.
Instructive-Reading. Mathematical-Tools. DSPRelated.com. Scientific-Tools. Manchester Data Encoding for Radio Communications. Abstract: Manchester encoding has gained wide acceptance as the modulation scheme for low-cost radio-frequency transmission of digital data. This form of binary phase-shift keying is a simple method for encoding digital serial data of arbitrary bit patterns without any long strings of continuous zeros or ones, and having the encoding clock rate embedded within the transmitted data. Manchester encoding is a form of binary phase-shift keying (BPSK) that has gained wide acceptance as the modulation scheme for low-cost radio-frequency (RF) transmission of digital data. Manchester is a simple method for encoding digital serial data of arbitrary bit patterns without having any long strings of continuous zeros or ones, and having the encoding clock rate embedded within the transmitted data.
The encoding of digital data in Manchester format defines the binary states of "1" and "0" to be transitions rather than static values. Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. 70874-90023.pdf (application/pdf Object) Eye pattern. Graphical eye pattern showing an example of two power levels in an OOK modulation scheme.
Avionics designers plan for another decade with the 1553 databus. Zero crossing. Cloud computing. Cloud computing metaphor: For a user, the network elements representing the provider-rendered services are invisible, as if obscured by a cloud. Non-return-to-zero. 37937_xpc_target_selecting_hardware_guide.pdf (application/pdf Object) Common-mode rejection ratio. The common-mode rejection ratio (CMRR) of a differential amplifier (or other device) is the rejection by the device of unwanted input signals common to both input leads, relative to the wanted difference signal. An ideal differential amplifier would have infinite CMRR; this is not achievable in practice. Encoding.pdf (application/pdf Object)
Certification - Institute of Management Consultants USA. Certification is one of the main reasons why IMC USA and more than 40 other management consulting institutes around the world exist. After you join IMC USA, you are strongly encouraged to pursue certification as evidence of your commitment to management consulting as a profession. The Certified Management Consultant™ (CMC®) certification is awarded by the IMC USA to consultants who have met global standards of performance that includes professional standards in technical competency, ethics, consulting competencies, professional behavior, client and project management, and personal conduct. Ascii Table - ASCII character codes and html, octal, hex and decimal chart conversion.
A Sensor Model Language: Moving Sensor Data onto the Internet. April 1, 2003By: Mike Botts Ph.D., University of Alabama in Huntsville, Lance McKee, Open GIS Consortium A new XML encoding scheme may make it possible for you to remotely discover, access, and use real-time data obtained directly from Web-resident sensors, instruments, and imaging devices. Members of the Open GIS Consortium, Inc. (OGC), including NASA, the National Imaging and Mapping Agency, and EPA, are developing a standard XML encoding scheme for metadata describing sensors, sensor platforms, sensor tasking interfaces, and sensor-derived data (see Editor's Note). The goal is to make all types of Web-resident devices (e.g., flood gauges, stress gauges on bridges, mobile heart monitors, Web cams, and satellite-borne earth imaging devices) discoverable and accessible using standard services and schemas.
The Sensor Model Language (SensorML) is a vital component that provides sensor information necessary for discovery, processing, and georegistration of sensor observations. Filtering Sensor Data with a Kalman Filter — Interactive Matter. Some days ago I wrote about noise with a LIS302DL accelerometer. Mil-std-1553. PSpice for digital communications ... Página ii Preface xi Fourier Analysis, Signals, and Bandwidth 1 1.1 Digital Signals 1 1.2 Bandwidth 2 1.3 Pulse Spectra for Different Pulse ...
MATLAB Central - Newsreader - Simulink 1553 bloc problem. Can't do broadcast ... MIL-STD-1553Tut.pdf (application/pdf Object) Honeywell Into the Blue Readership Survey. Into the Blue. Intotheblue-15.pdf (application/pdf Object) Propagation Delay.