Legacy PLC Memory Modules Are Getting Harder to Source: What Changed in 2026

If your team has noticed longer lead times or higher prices on memory modules for legacy PLCs this year, you’re not imagining it. Several industry sources have flagged 2026 specifically as the point where sourcing obsolete PLC components shifted from an occasional inconvenience to a real operational risk — and legacy memory modules are one of the parts most affected.

What’s actually being reported

One industry source (Central Surplus, dated 24 August 2026) points to a sharp jump in DRAM pricing — reportedly up 80–90% in a single quarter — driven by unrelated demand from AI data-center manufacturing pulling capacity away from the older, lower-margin memory types that legacy industrial controllers depend on. The framing used in that reporting is blunt: “the new part is on allocation, and the old part doesn’t exist” — meaning current-generation memory production isn’t a substitute for what a 20-year-old PLC actually needs, and that older memory type simply isn’t being made anymore.

Separate 2026 reporting (Industria X Plc, and Robotics & Automation News, both dated March–April 2026) frames the broader issue the same way: sourcing obsolete PLC components has become slow, expensive, and unpredictable enough that even a single failed module can now halt production and delay timelines. That’s a meaningful shift from a routine spares-management task to something closer to a supply-chain risk that needs active planning.

What this means in practice, not just in headlines

We’re presenting this as market context, not a claim about any specific customer situation — but the practical implications are straightforward for any plant still running legacy controllers:

• Waiting until a memory module actually fails to start sourcing its replacement is a riskier strategy in 2026 than it was a few years ago.
• Price volatility on discontinued components tends to move in one direction — up — as supply tightens further.
• A single point of failure (one memory module, one processor) can now represent real production risk if no sourcing plan exists ahead of time.

What a maintenance team can actually do about it

None of this changes the underlying sourcing discipline that already applies to any obsolete part: identify the exact catalog number and revision on the unit you have, don’t assume “PLC memory module” is specific enough to source correctly, and start the search before the part fails rather than after. We’ve covered this same identification discipline in more depth for a related platform in our Allen-Bradley SLC 500 sourcing article.

Beyond identification, the practical response to a tightening market is simply earlier action: audit which legacy controllers on your floor are running memory types that are getting harder to source, and start that sourcing conversation now — not during an unplanned stop.

Legacy PLC memory sourcing — direct answers

Why are legacy PLC memory modules getting more expensive in 2026?
Industry reporting attributes it primarily to DRAM price increases this year, driven by demand from unrelated sectors (notably AI data-center hardware) pulling capacity away from the older memory types industrial controllers depend on — combined with the simple fact that no one manufactures new units of these discontinued controllers.

Should I stockpile spare memory modules now?
That’s a plant-specific risk decision, not something we can generalize — but the reporting above supports the general principle that waiting until failure is a riskier strategy than it used to be for this category of part.

Is this specific to one PLC brand?
The reporting we’ve cited discusses the obsolete-PLC sourcing market broadly, not one brand specifically. The underlying issue — legacy memory types no longer being manufactured — applies across brands that use older memory technology.

Need to identify or source a specific module?

Send the exact catalog number and any revision marking from your unit to Ask Star, and our sourcing desk can tell you honestly whether that specific part can currently be located.