Here’s the challenge Omron’s Networked Systems Product Manager Dave Kaley proposed: Where’s there cost savings at installation and over the long run based on choosing distributed I/O handled by DeviceNet compared to standard wiring? His sample system called for 100 I/O points (all 3-wire devices) distributed over a 50-ft length with 10 drops of 3-ft length, using 18 AWG wire. The first startling revelation was that the cost of all materials was just about the same in terms of junction boxes for standard wiring vs. T-joints for DeviceNet. That left the focus on the labor costs and code-required equipment. The table below compares the two installations and reveals just how labor-intensive the standard wiring approach can be. Choosing DeviceNet removes the barriers to machine expansion and the addition of a few more I/O points presented by standard wiring.