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 two drive families: DigiFlex Performance and AxCent, made up of digital and analog drives respectively.

servo drive manufacturingThe DigiFlex Performance Series was introduced in 2008, has been updated continuously since.

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.

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 drive powerWith 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!