We've used basic PLCs and I/O for machine control for a long time. Our machines have to do more than before, and we need more connectivity options and a more COTS, standards-based approach to hardware and programming. Some customers are on the PAC bandwagon and think it's the next step for them and us. There are different opinions of what a PAC is. PLC vendors say they make PACs. So do PC-based control suppliers. Does it matter?

Send us your comments, suggestions or solutions for this problem. We'll include it in our October '12 issue. You can comment here or email us at controldesign@putman.net. Please include your company, location and title in the response.