Our machines use a variety of proximity switches to detect presence or absence. These switches have been hardwired to local I/O at our central PLC. We think it might be time to upgrade and move to switches connected to our PLC via a digital network to cut wiring costs and add diagnostics. Our concerns are the complexity of adding a network and, most importantly, real-time performance because we'll be depending on the network for speed of execution and ultimately the safety of our machine. What's been the experience of others in a similar situation to ours--machine builders that have made the upgrade from hardwired to networked proximity switches?
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