Accuracy as it relates to the measurement of electrical signals would seem to be a simple, straight-forward concept. In the simple case, a reading as shown in a digital display could be compared to that of a perfectly accurate instrument. The discrepancy, if any, could be expressed as a fraction of a percent. The difficulty […]
FAQ
In search of accurate measurements — The speed of light
If an instrument is to give accurate measurements, it must first have been calibrated to a standard. In metrology, a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures, […]
Basics of the FlexRay Bus
As automobile development has continued apace, some new highly complex and critical subsystems have emerged. Simple networks such as CAN Bus and LIN Bus have long handled communications among controllers and electromechanical automotive systems, but an enhanced communication bus eventually became necessary to handle higher-bandwidth connections. Accordingly, a consortium developed standards for what came to […]
Exploring the LIN bus with an oscilloscope
The Local Interconnect Network (LIN) Bus was created to augment CAN Bus, at first in automotive applications and later for industrial use. CAN Bus was developed by Bosch to serialize communication among automotive electrical systems. It is a good candidate where high-bandwidth and advanced error-handling is needed as in automotive engines, where transmission and braking […]
Exploring the CANbus with an oscilloscope
The Controller Area Network (CAN) Bus was introduced in 1983 by Robert Bosch GmbH, a multinational engineering and electronics company headquartered in Germany. CAN Bus was originally designed to let microcontrollers and devices communicate without a host computer. It was primarily intended for automotive applications but is currently used additionally in elevators, video games, human […]
Testing and measurements with RS-232
The trapezoid-shaped 25-pin array inside the rectangular connector was a familiar sight a few years back, in an age when computers were connected primarily by means of the RS-232 bus. This old protocol seems rather clunky today alongside sleek new USB schemes with their many user benefits. However, RS-232 is far from obsolete. It is […]
Analyzing the Serial Peripheral Interface (SPI) bus
A serial bus can be more efficient than the traditional parallel bus. But there are challenges in representing and making sense of the serial data flow in the context of clock timing. These difficulties can be resolved by using the multi-channel capabilities of advanced oscilloscopes such as the Tektronix Series 3000 instruments. The key to […]
Basics of working with I2C buses
Back in olden days, parallel buses were used to link electronic building blocks. Today serial buses have largely replaced them. There are numerous components for many applications that have standard serial interfaces, and this trend makes serial technology a good choice for design engineers. Because there are fewer signal lines, serial bus electronics take up […]
Basics of induction
Building on the work of others, particularly Humphry Davy, Hans Christian Ørsted and Alessandro Volta, English researcher Michael Faraday formulated his Law of Electromagnetic Induction. This most basic of all laws governing electromagnetism quantifies the interaction of a magnetic field and an electric circuit, producing electromotive force (EMF) or in the language of technicians and […]
Basics of interferometers
Interferometers figure prominently in the history of experimental physics. They were at the heart of the Michelson-Morley Experiment of 1887 that attempted unsuccessfully to detect the existence of an ether wind, a hypothetical medium for light transmission. (The null result was not because of any inadequacy in the instrumentation or deficiency in the design of […]
