I don’t buy clothes often. I tend to wear the same things over and over again until they wear out. When I do break down and buy something, I don’t expect one brand will serve all of my needs. Shopping would be less painful if Levi’s made everything that I wear, but I doubt that I would look very good or be very comfortable wearing denim shoes, denim socks, denim underwear and denim shirts. You get the point.
Though we all realize the “one brand fits all approach” doesn’t work when buying clothes—or anything else for that matter—for some reason, many original equipment manufacturers (OEMs) and end users take this approach with their control system projects. Calling just one manufacturer of hardware or software may simplify your search, but is their solution the best one for your needs?
If you’re shopping for a better automation system, be sure to fully consider the following questions, which are common to almost any automation project or upgrade:
-
Processor: Programmable logic controller (PLC), programmable automation controller (PAC) or distributed control system (DCS) based system or possibly a personal computer-based control system?
-
Operator interface: A stand-alone human machine interface (HMI) or possibly an enterprise wide supervisory control and data acquisition (SCADA), manufacturing execution system (MES) or enterprise resource planning (ERP) system?
-
Motion: Across-the-line starters, servos, steppers, variable frequency drives (VFDs), direct current (DC) drives?
-
Input/Output: Local and distributed or centrally located?
-
Safety: Light curtains, scanners, guard switches, safety-rated relays and contactors, safety PLC?
-
Network: Private or corporate?
-
Energy management: Energy use analysis and control?
In addition to these big picture questions, other questions that often need to be addressed include:
-
Extent of data collection and reporting?
-
Remote access for maintenance and support?
-
Communication protocol to integrate all of the equipment into a cohesive network?
-
What level of support is available?
Perhaps the most important question that you should be asking is, “Who will give me the best engineered solution using best-in-class products and services, specifically for my application?” Is the answer the big, global manufacturer that can only sell their hardware and services? Or the control system integrator who has experience across multiple manufacturers and will engineer the best solution for your needs?
When you consider all of the various aspects of the project, will one brand fit all? Probably not. Then why would your first phone call be to a manufacturer? If you call the manufacturer first, be prepared to be sold denim underwear.
Stephen Blank is chief executive officer of Loman Control Systems Inc., a certified member of the Control System Integrators Association.
