Drive and PLC Systems
A short overview

The Motion Control Equipment manufacturers  have done an excellent job at improving both the quality and standard features of their equipment. It's rare these days for  equipment not to work, and like most electronics, the costs have actually gone down.

There was a time when commissioning engineers spent the majority of their time just getting the drives and PLCs to sequence properly, and once started, to run the motors at the correct speed and remain stable. Simply getting this to happen, sometimes took weeks.  Those problems began to fade as the equipment manufacturers began to incorporate auto-tuning and auto-correcting software, in tandem with their overall improved quality and lower failure rates.

The issues now faced by commissioning engineers and system designers often have more to do with communications as plant engineers demand more real time information and coordination of their processes. Again, the Motion Control  manufacturers have made these tasks much easier with onboard selectable communication protocols, built in PID loops, and responsive equipment.  The Human Machine Interface (HMI) is growing in importance within drive systems.  Younger operators especially, having been immersed in graphic user interface all of their lives, expect the machine controls to not only resemble a regular computer interface, but to operate just as easily.

The lines between PLCs and Industrial Computers have blurred, and in some recent systems designed by EMA, computers have been used in lieu of PLCs. There are tradeoffs in performance and cost that must always be considered, and often it comes down simply to what the plant engineer wants. While we don't see PLCs going away anytime soon, there are many more options available today. What's often described as an industrial touch screen, is in fact, an industrial computer which in some cases, has enough I/O to replace a PLC.

EMA does systems that range from simple DC Extruder Drives to complex material winders, to large dynamometers. Our equipment and systems can be found anywhere from the NYC subway tunnels, to servo controlled corrugated lines, to oil platforms, to HVAC systems.

The controls can range from a simple Hand/Off/Auto switch, to a computer controlled interface that displays real time machine parameters on the plant manager's desktop.

We often get asked a question like "can the drive (or PLC or system) do ___ ?"  The short answer, these days, is always "yes, it can."  It's a little like asking "can my desktop computer back itself up every day?"  The answer is "yes, are you sure you want it to?"  Since we can design motion control and automation systems to do just about anything, the question isn't' "will it do it?"  It's, "do I want it to?"

EMA Drive Lines..  March  2007

Click on the Systems link on the left and visit our systems page. EMA is a full automation and control solutions provider.