Motors & Drives Information

With the increased use of digital drives on NC machines, there is mounting concern that a universally accepted standard for connecting digital drives (both servo and spindle) to CNCS is long overdue. Is there hope for a universal standard in the near future? This article attempts to answer that question along with providing a status update of the various organizations working on a digital drive standard.

Why Do We Need An Interface Standard For Digital Drives?

Since the introduction of electric servo drives over 15 years ago, industry has benefited from a common interface standard enabling machine designers and end users to specify the brands of servo motors and drives independent of the control. This interface, commonly referred to as an analog interface, is defined by the Electronic Industries Association (EIA) RS-431 and the International Electrotechnical Commission (IEC-550) as a connection utilizing a [ + or - ]10 volt command signal to the drive unit. This simple universal analog interface has allowed servo and spindle drives to be selected on the basis of performance, compatibility or other preference independent of the control unit.

Digital drive technology offers enhanced capability well beyond what is possible with analog drives which is what makes them so desirable. Included in this enhanced capability are functions such as: increased path accuracy; static friction compensation; ability to reprogram the drive for enhanced slide performance; and freedom from thermal drift. Along with this increased capability comes the potential for lower cost if their prices follows the downward trend which has been projected.

# posted by Medical Information : 5:40 AM