Analog and Digital: Which is the Way to Go?

Analog and Digital Servo DrivesADVANCED Motion Controls began with a few simple analog servo drives that were designed on a kitchen table in 1987. Later in the 90s, we began manufacturing our very own line of off-the-shelf digital servo drives for more sophisticated applications.

Nowadays, we offer custom servo drives and off-the-shelf products for virtually every industry, from autonomous mobile robots and automated guided vehicles to telescopes and underwater cameras.

Despite numerous changes to labor and manufacturing across all industries, many of our classic drives are still in use today. Our current line of drives fall into three servo drive families: DigiFlex® Performance, AxCent, and FlexPro®, two of which are digital while the other is analog.

servo drive manufacturingAs the name would suggest, the DigiFlex Performance Series is one of our digital servo drive families. Since its introduction in 2008, it has become our largest servo drive family, making up the majority of our drive selection.

The AxCent Series, introduced in 2016, is considered our most reliable and best-selling analog servo drive series to date. This series modernized our long standing analog products with consolidated features, updated components and increased performance.

FlexPro was introduced in 2019 as our latest digital servo drive family, featuring new technologies and unrivaled power density. Over a dozen FlexPro products were added in the year since its release with more on the way!

Both analog and digital servo drives offer unique value for different applications. Available in panel mount, PCB mount, or vehicle mount form factors, both drive archetypes offer unique advantages over the other for broad applications.

You may even be surprised to hear that analog and digital servo drives make up an approximately equal proportion of our sales. To help you understand the differences between analog and digital servo drives, we’d like to outline the advantages of choosing one over the other for any specific task.

Advantages of Analog Servo Drives

analog servo drivesDespite what you may think, analog servo drives offer great value for a wide variety of simple and sophisticated motion control applications. The number one reason that many companies invest in analog servo drives is that they cost less at purchase and for repair.

They’re also tried and true technology. They only need a small screwdriver to configure as opposed to a computer connection. They’ve had many more years of use, so the designs are very robust, and the mechanical infrastructure of analog servo drives make them easy to repair and troubleshoot.

Aside from this, analog drives offer numerous other advantages:

  • Easy setup and installation
  • High bandwidth
  • Instantaneous updating (no microprocessor time)
  • Adaptable to form and factoranalog drive power
  • Wide selection of choices

For example, at AMC, we offer tiny plug-in analog drives designed for tight spaces, as part of our µZ series.

But there are also some obvious drawbacks to investing in an analog servo drive. Not only do they offer no intelligence to act on their own, they also require manual tuning (setting switches, turning of potentiometers for adjustments) to operate. Of course, once the best configuration has been determined on the first unit, it is easy to replicate on subsequent units in production.

Despite needing centralized control to operate, analog servo drives still provide the precision and reliability that manufacturers desire from servo drives in the first place.

Advantages of Digital Servo Drives

digital servo drivesOn the other end of the spectrum lie digital servo drives, which offer the intelligence to complete actions on their own and communicate over a centralized or distributed network.

The main benefits of digital servo drives include:

  • Easy configuration (no manual tuning required)
  • High power density
  • Flexible control type after configuration
  • Precise fault indication – can transmit the reason for a fault condition
  • Centralized or distributed network control

digital servo drive power rangesWith their built-in intelligence and programmability, digital servo drives have been rapidly advancing with new features and capabilities. Over time, digital drives are getting smarter, smaller, and more powerful.

Digital drives tend to be more expensive than their analog counterparts. However, with new developments each year, the gap is closing, and many companies are switching to digital.


Concluding Thoughts

analog and digital servo drivesDoes this mean that digital drives are a superior technology? In most cases, yes. Does this mean you should definitely invest in digital over analog? Not necessarily.

Analog and digital servo drives offer their own unique advantages and, in many cases, analog servo drives offer enough capabilities to get the job done. This is especially true when you have an intelligent controller. Ultimately, it comes down to budget and application.

If you have the budget, and you need a very high-performance drive, special features, or the controller isn't very intelligent, digital is worth it. But analog devices also offer many of the same benefits, even though they are not as sophisticated. If you have a good controller, then an analog drive can do the trick.

To find out which servo drive would be best for your specific application contact us today!


Update History:
May 4th, 2020 - added FlexPro to our description of drive families.

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