The industrial automation landscape is undergoing a profound transformation.
The diagram above illustrates the
industry trends, adoption evidence, and career implications that position SCL
as the future standard for industrial automation. The convergence of
Industry 4.0, edge computing, artificial intelligence, and cloud integration is
reshaping how factories operate and how engineers approach automation. At the
center of this transformation is Structured Control Language (SCL), which is
increasingly becoming the de facto standard for new PLC development. This
article examines whether SCL represents the future of industrial automation and
what this means for engineers building careers in this field.
The Convergence of IT and OT
For decades, Information Technology (IT) and Operational
Technology (OT) operated in separate worlds. IT focused on business systems,
data management, and connectivity. OT focused on controlling physical
processes, with reliability and determinism as paramount concerns. This
separation meant that automation engineers could remain largely isolated from
broader IT trends.
This separation is dissolving. Modern factories require
seamless integration between production systems and enterprise IT
infrastructure. Data must flow from machines to analytics platforms. Machine
learning models must run at the edge. Cloud services must coordinate with local
control systems. This convergence demands that automation engineers adopt
practices and tools from the IT world.
SCL, being a text-based language with similarities to
mainstream programming languages, facilitates this convergence. Engineers
trained in SCL can more easily collaborate with software developers, utilize
modern development tools, and integrate with IT systems. This is a fundamental
shift in how automation engineering is practiced.
Evidence of SCL's Growing Adoption
The evidence for SCL's rising prominence is substantial.
Siemens, the market leader in industrial automation, has made SCL a first-class
citizen in TIA Portal. Educational institutions worldwide are incorporating SCL
into their curricula. Industry surveys consistently show that SCL proficiency
is increasingly valued in job postings.
A 2024 analysis of automation job postings revealed that
SCL skills are mentioned in 45% of PLC programmer positions, compared to just
15% five years earlier. This trend is accelerating. Companies like Bosch,
Volkswagen, Siemens itself, and other manufacturing leaders have publicly
committed to transitioning their automation infrastructure to SCL-based
systems.
The open-source community has also embraced SCL. Projects
like OpenPLC and various industrial automation frameworks support SCL, making
it accessible beyond proprietary Siemens ecosystems. This democratization of
SCL is accelerating its adoption.
The Advantages That Drive Adoption
Several factors drive SCL's adoption as the industry
standard:
Alignment with Software Engineering
Practices: SCL enables automation engineers to adopt proven software
engineering practices—version control, continuous integration, automated
testing, code review. These practices improve code quality and reduce
development time.
Scalability: As automation
systems grow in complexity, SCL's support for modularity, encapsulation, and
code reuse becomes increasingly valuable. Large projects that would be unwieldy
in Ladder Logic are manageable in SCL.
Integration Capabilities: SCL
facilitates integration with enterprise systems, cloud platforms, and IoT
ecosystems. This is essential for Industry 4.0 applications.
Developer Productivity:
Experienced programmers can implement complex logic faster in SCL than in
graphical languages. This translates directly to cost savings.
Talent Pipeline: As more
educational institutions teach SCL, the talent pool of engineers skilled in SCL
grows. This creates a positive feedback loop—more SCL expertise available means
more organizations adopt SCL.
Challenges to Universal Adoption
Despite SCL's advantages, challenges remain to universal
adoption as the industry standard:
Legacy Systems: Millions of
lines of Ladder Logic code run in factories worldwide. Rewriting this code in
SCL is economically impractical. Legacy systems will continue operating in
Ladder Logic for decades.
Skill Gaps: Many experienced
automation engineers learned Ladder Logic and have not transitioned to SCL.
Retraining requires time and investment. Some organizations struggle to find
SCL-skilled engineers.
Standardization: While IEC
61131-3 provides a standard for SCL, different vendors implement it
differently. Siemens SCL differs from Beckhoff TwinCAT or other
implementations. True standardization remains elusive.
Safety Certification: Some
safety standards have extensive documentation and verification procedures for
Ladder Logic. Equivalent procedures for SCL are still developing. This can slow
adoption in safety-critical applications.
Learning Curve: For
electricians and technicians without programming backgrounds, SCL has a steeper
learning curve than Ladder Logic. This can be a barrier in organizations where
the automation team has primarily electrical backgrounds.
The Hybrid Future
Rather than a complete replacement of Ladder Logic with
SCL, the most likely scenario is a hybrid future where both languages coexist
for decades. New projects will increasingly use SCL, but legacy systems will
continue operating in Ladder Logic. Organizations will adopt hybrid approaches,
using each language where it is most appropriate.
Predicted Evolution:
•
2026-2030: SCL adoption
accelerates. 60-70% of new projects use SCL. Legacy Ladder Logic systems
continue operating. Mixed projects using both languages become common.
•
2030-2040: SCL becomes
dominant for new development. Ladder Logic primarily used for maintenance of
legacy systems. Younger engineers predominantly use SCL.
•
2040+: Ladder Logic becomes
a legacy language, maintained primarily by specialists. SCL is the standard for
industrial automation programming.
Career Implications for Next-Generation Engineers
For engineers entering the field today, the career
implications are clear: SCL proficiency is essential for
career advancement.
Why SCL Skills Matter:
1
Marketability: Employers
increasingly seek SCL skills. Engineers with SCL expertise command higher
salaries and have more job opportunities.
2
Future-Proofing: Learning
SCL ensures your skills remain relevant as the industry evolves. Ladder Logic
expertise alone will become increasingly obsolete.
3
Broader Opportunities: SCL
skills open doors to roles in Industry 4.0 projects, edge computing, and
IoT—areas with significant growth potential.
4
Collaboration: SCL enables
collaboration with software engineers and IT professionals, expanding career
opportunities beyond traditional automation roles.
5
Innovation: SCL facilitates
implementation of advanced algorithms, machine learning, and predictive
maintenance—areas where innovation is happening.
Recommendations for Next-Generation Engineers
1. Master Both Languages:
While SCL is the future, understanding Ladder Logic remains valuable. Many
systems still use it, and understanding both languages makes you more
versatile.
2. Learn Software Engineering
Practices: Beyond SCL syntax, learn version control, testing, design
patterns, and software architecture. These skills are increasingly important in
automation.
3. Understand the Broader Ecosystem:
Learn about Industry 4.0, IoT, cloud platforms, and data analytics. Automation
is increasingly integrated with these technologies.
4. Develop Communication Skills:
As automation becomes more integrated with IT, the ability to communicate with
software engineers and business stakeholders becomes crucial.
5. Stay Current: The field is
evolving rapidly. Commit to continuous learning. Follow industry trends, take
courses, and experiment with new technologies.
Organizational Strategies for SCL Adoption
For organizations considering SCL adoption, several
strategies prove effective:
Pilot Projects: Start with
new, non-critical projects. This allows teams to gain experience without
risking production systems.
Hybrid Approach: Use SCL for
new modules while maintaining existing Ladder Logic. This reduces risk and
allows gradual transition.
Training Investment: Invest in
training for your team. The learning curve is manageable for engineers with
programming backgrounds, and the payoff is significant.
Coding Standards: Establish
SCL coding standards early. This ensures consistency and makes code more
maintainable.
Tool Integration: Adopt
version control, continuous integration, and automated testing tools designed
for SCL. This improves code quality and development efficiency.
The Role of Artificial Intelligence
Looking further ahead, artificial intelligence is
beginning to influence automation programming. AI-assisted code generation,
automated testing, and intelligent debugging tools are emerging. SCL's
text-based nature makes it more amenable to AI tools than graphical languages.
This is another factor driving SCL adoption.
Future automation engineers may spend less time writing
code and more time designing systems and validating AI-generated code. This
shift further emphasizes the importance of understanding software engineering
principles, which SCL facilitates.
SCL is not just the future of industrial automation—it is
increasingly the present. The evidence is overwhelming: adoption is
accelerating, educational institutions are teaching it, employers are seeking
it, and the industry is moving toward it. While Ladder Logic will remain
relevant for legacy systems and simple applications, SCL has become the
standard for new development and complex projects.
For next-generation engineers, this represents both an
opportunity and a necessity. The opportunity is to build careers in a field
undergoing exciting transformation, with access to advanced technologies and
integration with broader IT ecosystems. The necessity is to invest in learning
SCL and modern software engineering practices to remain competitive.
The engineers who embrace SCL and develop expertise in
modern automation practices will be the leaders of the industry's next chapter.
Those who cling to legacy skills risk becoming obsolete. The choice is clear:
the future belongs to those who master SCL and the practices it enables.
References
[1] Siemens Automation 2026 Vision - https://www.siemens.com/industrial-automation
[2] Industry 4.0 Trends Report 2024 - https://www.mckinsey.com/industries/automotive-and-assembly/our-insights
[3] Automation Career Trends - https://www.indeed.com/career-advice/careers/automation-enginee
[4] IEC 61131-3 Standard Evolution - https://en.wikipedia.org/wiki/IEC_61131-3
[5] Edge Computing in Industrial Settings - https://www.ibm.com/cloud/what-is-edge-computing