Well, I just put together all the great input from a bunch of machine builders about how they support and when they decide to renovate legacy machines for Control Design's June cover article, "Old Machines, New Lives," and practially everyone has some good advice.

We do a lot of controls upgrades including panels with a lot of old mechanical relays. Our first response is to simply replace them all via PLCs. Some of the non-variable functions, though, are ideal for relays, and many of the installations are in high-EMI areas where relays do better...