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Ultrasonic sensors can detect objects that many traditional sensing technologies cannot because of their ability to see targets regardless of color, transparency and surface texture. Even in dusty, humid, or hazy environments, they may be the only sensor that is able to provide the desired results. Ultrasonic sensors are often used in liquid level measurement applications and detecting clear films.
Ultrasonic sensors emit a burst of short, high frequency sound waves that propagates in a cone shape towards the target. When the sound waves strike the target, they are bounced back to the sensor. The sensor then calculates the distance based on the time span from when the sound was emitted until the sound was received.
In numerous types of analog position sensors, resolution is expressed in terms of bits, e.g, 8-bit, 12-bit, 16-bit, etc. But what does that really mean? In a previous entry, I discussed what I called Digitally Derived Analog Signals, which provides a basic overview of how Digital-to-Analog Converters (DAC’s) are used to generate analog sensor signals. You may recall from that entry that when someone says a sensor has “16-bit resolution”, what they really mean is that the sensor employs a 16-bit DAC, which is capable of processing 216 discrete values, and representing any one of those values as a corresponding analog signal.
To help better understand what these binary numbers actually mean, I thought it might be helpful to provide a quick-reference chart showing the equivalent decimal values of numbers from 20 to 232.
As many machine builders, OEMs, individual plants, and large corporations decide to move from the “bus” to the “net” (Profibus or DeviceNet to Profinet or EtherNet/IP) they have a chance to look at all the new architectures available and decide on which is the best for them. Here are the first two topics to take into consideration:
Sometimes the things that seem the simple can be the most confusing. In the world of the photo sensor, the principle of “light-on” vs. “dark-on” is one of these things. What am I talking about you might ask? Let’s see if I can help define these concepts.
I recently watched a short webinar recorded by the PI North America organization and it really helped me understand the basics of how ethernet communication comes together. There are so many protocols and standards and they all communicate on the same media. Carl and Hunter do a good job presenting ethernet in a technical but easy to understand way.
The webinar is here. Their topics include:


