I totally get your frustration! It's incredibly frustrating when manufacturers discontinue critical PLC modules that still have years of useful life left in your installed systems. From what I've researched, manufacturers typically discontinue modules for several business-driven reasons: component obsolescence (the chips and parts inside become unavailable), production inefficiency (making small batches of old parts isn't profitable), and strategic product lifecycle management (they want to move customers to newer platforms).

The ethical responsibility question is really important here. While manufacturers aren't legally required to support products indefinitely, there's a strong ethical argument that they should provide reasonable support for critical industrial equipment. Many experts argue that OEMs should offer extended support periods, provide migration paths, or partner with legacy equipment manufacturers (LEMs) who can continue producing and supporting discontinued components. Some companies are actually doing this - GDCA, for example, is authorized by OEM partners to continue manufacturing and repairing legacy products using original specifications.

The reality is that pushing expensive upgrades while abandoning functional systems creates real problems for manufacturers who rely on these systems. It's not just about cost - it's about production continuity, safety, and the environmental impact of replacing equipment that still works. What's your specific situation with PLC modules? Are you dealing with a particular manufacturer or system that's causing headaches?