PLC and Distributed Control System Patents: Who Leads and Where the Claim Space Is Still Open
23.7% sits with five filers. the top five combined account for 6,895 of the 29,144 records in scope, with a long tail of single-digit and single-filing entrants behind them. Filings rose to 2,226 in 2021, the high point of the series, then fell to 1,421 by 2024 -- a 36% decline over that three-year span. Publication lags filing by roughly 18 months, so the lower counts shown for 2025 and 2026 reflect incomplete data rather than a continued slide; treat only the 2021-2024 comparison as a reliable read on direction.
- 1INTERNATIONAL BUSINESS MACHINE CORPORATION9.1%
- 2AT&T INTELLECTUAL PROPERTY I L P6.1%
- 3FISHER ROSEMOUNT SYST INC3.0%
- 4DELL PROD LP2.8%
- 5ROCKWELL AUTOMATION TECH INC2.6%
See the full plc & distributed control systems patent landscape analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions about this landscape
Who holds the most patents in PLC and distributed control system technology?
A single assignee leads the ranked field with 2,654 records, noticeably ahead of the fifth-ranked filer at 761 and the tenth at 379. The top five combined hold 23.7% of the 29,144 records in scope, and the top ten hold 31.8%, which means concentration is real at the very top but the majority of filings still belong to a long tail of smaller and single-filing entrants. The ranking includes 100 companies total, so it should not be read as a top-50 or top-100 list of the entire field -- it is the full ranked set the data covers.
Is patent filing in this space growing or shrinking?
Filing rose to a peak of 2,226 records in 2021, then declined to 1,421 by 2024, a 36% drop over that three-year span. That is a real and complete-data comparison. Counts shown for 2025 and 2026 look much lower still, but publication typically lags filing by roughly 18 months, so those years are undercounted rather than genuinely quiet -- the honest read is that growth cooled after 2021, not that filing has collapsed.
What technology areas do PLC and distributed control patents actually cover?
The largest IPC subclass in this corpus is G06F (general-purpose digital data processing) at 23.6% of records, followed by H04L (digital information transmission) at 16.4% and G06N (AI-based computing) at 11.6%. The classic control-and-regulation subclass, G05B, sits lower at 11.4%. Because a single record can carry several IPC codes, these percentages add up to more than 100% of the total -- they show where claim density concentrates, not exclusive categories.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on PLC & Distributed Control Systems Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.