I've been managing procurement for a mid-sized industrial automation integrator for about 7 years now. Our annual spend on PLCs and related components runs around $180,000. Over that time, I've negotiated with 8+ vendors, compared quotes across Siemens, Allen-Bradley, and a few smaller players, and built a cost-tracking spreadsheet that's become my bible.
This article answers the questions I get asked most — by our own engineers, by new clients, and by folks in forums who are trying to figure out Siemens PLCs. It's not a sales pitch. It's the stuff I wish someone had told me when I started.
Honestly, it depends on how you measure it. According to industry analysis from ARC Advisory Group and Omdia, Siemens holds the largest market share in the global PLC market as of 2024. Their share is around 30-33% depending on the report, with Rockwell/Allen-Bradley trailing at roughly 20-22% (Source: ARC Advisory Group, PLC Worldwide Market Analysis, 2024).
But — and this matters — market share varies by region. If you're in North America, you might see way more Allen-Bradley. In Europe and Latin America, Siemens dominates. We're based in Mexico, and I'd say 60% of the PLCs we see specify Siemens. So yes, globally, Siemens is #1, but your mileage varies.
This decision kept me up at night the first time I had to spec a new line. I went back and forth between the S7-1200 and S7-1500 for about three weeks.
Here's the short version:
I almost went all S7-1500 because "bigger is better" — but that would've tripled our cost for the smaller lines. So glad I didn't. The S7-1200 does the job for those. The TCO difference was way bigger than I expected.
I've seen varying numbers, but the most cited figure from automation market analysts puts Siemens at about 30-33% market share in 2024 (Source: multiple analyst reports including ARC Advisory Group, 2024). That's slightly down from their peak around 2019, because competitors like Rockwell and Schneider/Mitsubishi have been aggressive in some regions. But it's still the biggest single slice of the pie.
For context, the global PLC market is roughly $12-14 billion annually. So Siemens' piece is about $4 billion. That's a lot of controllers.
About twice a year, Siemens publishes security advisories for their industrial products. The most frustrating part of this: the media makes it sound like the world is ending. Actually, Siemens is more transparent than most.
Advisories typically mean they've found a vulnerability in a specific firmware version (e.g., S7-1500 firmware V2.x) and are releasing a patch. In Q2 2024, I had to plan a firmware update on three S7-1500s due to an advisory. The actual risk was low — it required physical network access to exploit — but we did it anyway per our security policy.
Key takeaway: Register for Siemens industrial security notifications. It's free. Update firmware on schedule. Don't panic.
For modern S7-1200 and S7-1500 controllers — no. You need TIA Portal (Totally Integrated Automation Portal). That's the software. For older S7-300/400, you could use the legacy Step 7 software, but Siemens discontinued new licenses for Step 7 V5.x in 2022. They're pushing everyone to TIA Portal.
This is a real pain point if you're migrating. The TIA Portal licensing model changed a few years ago. In 2023, when we upgraded our TIA Portal from V16 to V18, we had to buy a new "floating network license" because our old one didn't transfer. That 'free upgrade' I thought we were getting? Actually cost us about $1,200 in hidden license re-classification fees.
Short answer: not necessarily. Long answer: it depends on your discount tier.
When I audited our 2023 spending, I compared quotes for a medium-sized project (about 200 I/O, 3 drives, 1 HMI) from both Siemens and a Rockwell distributor. Siemens base hardware was roughly 10-15% cheaper. But the software (TIA Portal vs. Studio 5000) was roughly similar — about $2,000-3,000 for the basic engineering packages.
Training costs? Siemens has way more certified training centers globally, which keeps per-person training costs lower in our region. A Siemens basic PLC training course runs about $1,800 per person. Rockwell's equivalent — about $2,500.
This question comes up constantly. No, you don't need a "license" like a driver's license. You need a software license — a paid key for TIA Portal — and a valid product serial number for the controller. Siemens has gotten better: TIA Portal V18 and newer allow trial mode for 21 days with no license needed.
Regarding that One random question — no, you don't need a license to drive an electric bike in most places. But I'm pretty sure that's not what you're asking about your PLC.
I get this a lot from startups. So glad I tried this once before going all-in. I bought a used S7-1200 from a surplus reseller to test. It worked for about 2 hours then faulted. The firmware was obsolete and couldn't connect to our TIA Portal version. I spent 4 hours trying to force a downgrade, failed, and had to buy a new one anyway. That 'deal' cost me $200 and a half day of wasted time.
If you're just learning — a used one is okay for practice. For production? Buy new. The reliability difference is not worth the few hundred dollars.