When you need to make electronic measurements of any kind, you probably will consider using an oscilloscope or logic analyzer. However, those tools will only work when there is actually a signal to measure, and not everything that needs to be measured can make its own signal. When that happens, measurement can only take place if the signal is provided externally, and that’s where waveform generators come into play.
But what type of waveform generator do you need? There are several different types, all of which have a different purpose and create different types of waveforms. Because so many new products within the Internet of Things require signal generation, it’s important to select the right waveform generator to ensure that your device works properly and delivers accurate information to the user.
Waveform generators in brief
There are three main types of waveform signal generators: Function generators, arbitrary function generators, and arbitrary waveform generators.
A function generator generates periodic standard functions such as sine, square, triangle, ramp up/down, DC, and noise. Typically, they produce waveforms in sine, square, triangular, and sawtooth shapes. The least sophisticated waveform generators, function generators are not ideal when you need a stable waveform or a low noise. However, for testing electronic equipment like amplifiers, a function generator can produce a stable signal, or introduce an error signal as well as white noise, to ensure the proper function of the equipment.
An arbitrary function generator (AFG) is similar to a function generator, but also offers on-board memory space for a user-defined waveform. In addition to predefined sets of waveforms, the AFG also allows the user to define a waveform, save it in the generator’s memory, and then output it. This gives you the capability to define a waveform, store it to the AFG’s on-board memory, and then output the waveform using direct digital synthesis. AFGs are useful for testing similar applications and devices as the function generator, but give you the option of creating more unique waveforms for greater flexibility.
Finally, an arbitrary waveform generator (AWG) produces both the standard waveforms and large, complex, user-defined waveforms, including those that are linked or looped combinations for unique sequences. AWGs require the most memory of all types of generators and use a clocking scheme that allows the device to only create waves in the order in which they are placed in the memory. This puts some limitations on the frequency of output. In other words, while the user can define a specific waveform, the precision of that waveform may be limited.
Which waveform generator is appropriate for the specific device depends on the specific device and the need for precision in the waveforms. Cost, power use, safety, and security concerns also play a role.
Waveform generators and the IoT
Thanks to the growth of the IoT, waveform generators are seeing a sort of renaissance in terms of development. Embedded systems developers are, more than ever before, looking for waveform generators that are flexible, easy-to-use, and accurate. One of the major trends in waveform generator development, then, is to create generators that are able to work in both analog and digital modes and meet a wide variety of signal generation needs.
Some of the most common applications of waveforms are in the medical field, and the advances in waveform generation are already being seen in the delivery of patient care. For example, new technology allows for healthcare providers to automatically view waveform data on their mobile devices, giving them the chance to monitor and respond to patients in real time. Waveforms from telemetry devices are also being automatically recorded into electronic health records, not only giving providers access to the data in a timely manner, but reducing the risk of errors inherent in the manual transmission of data.
Waveform generation is also a key part of testing IoT devices. Communication channels need to be tested and debugged to ensure that messages between the device and the hub are being sent and received as expected. For these tests, sensors collect data and convert it to an analog waveform, which is then examined and compared to other waveforms to ensure proper function. Without the waveforms, though, there would be nothing to test.
Choosing the right waveform generator for your IoT device can make a significant difference in its function, not to mention the cost. As you develop your embedded system, compare the options and choose the generator that will best meet your expectations and requirements.
For more insight on the Internet of Things, see Live Business: The Digitization of Everything.