30.10.2026

Uncompromising Safety for Linear Motion – SIL 3 Linear Encoders

Uncompromising Safety for Linear Motion – SIL 3 Linear Encoders

Absolute precision meets the highest level of functional safety: The new linear measurement system with SIL 3 / PLe from TR Electronic.

TR Electronic is expanding its portfolio in the field of functional safety with a true innovation: a fully certified linear measurement system that meets the stringent requirements of SIL 3 and PLe (as well as SIL 2/PLd). With this, TR Electronic closes the gap in applications where linear motion must be monitored directly and with absolute safety. The system is based on highly reliable, redundant sensing, in which two independent measurement systems are housed in a single tube or profile in a protected manner.

Truly absolute, non-contact, and wear-free
This new development combines maximum safety with the proven mechanical advantages of TR Electronic’s linear measurement systems. Scanning is truly absolute, non-contact, and completely wear-free. Since there is no system-imposed speed limit, the measurement system effortlessly keeps pace even with highly dynamic processes. The system is available to users in either a tube or profile configuration and provides position data with a resolution of 0.01 mm.

Secure Communication and Smart Diagnostics
Secure data is transmitted directly via PROFINET and PROFIsafe (PROFIsafe address type 2). Integrated features such as the Media Redundancy Protocol (MRP) ensure maximum network availability. System startup is significantly accelerated by Fast Start-Up (FSU). In
addition, the system is perfectly suited for modern control environments thanks to the standardized PNO Encoder Profile (Class 3/4) and S2 system redundancy.

To ensure long-term safe operation, the measurement system features internal hardware diagnostics as well as continuous internal signal checking for plausibility and quality. A high-speed measurement channel for high-precision control and a secure preset interface are also directly integrated. Commissioning and service are conveniently handled via the TCI Device Tool.

Equipped for Cybersecurity and the New Machinery Regulation With an eye toward the future, the SIL3 linear measurement system is designed ex works to comply with the Cyber Resilience Act (CRA) and the new Machinery Regulation (MVO 2027), and meets the criteria of PROFINET Security Class 1.

PROFINET Security Class 1 incorporates the latest security mechanisms into the PROFINET protocol and protects individual components and the GDSML file from unauthorized access. This increases communication availability and supports a robust connection between the end device and the controller. ’ LM_I46+FS linear encoders with PROFINET benefit from the capabilities offered by so-called “H” controllers thanks to System Redundancy Level S2: The linear encoder maintains active connections to both instances of the secure controller simultaneously, so that if problems arise in one instance, operation can be seamlessly maintained by the other instance. This increases the availability of the entire system while ensuring functional safety.

Applications
The new SIL3 linear measurement system is indispensable wherever humans and machines work closely together and extremely heavy loads must be moved safely. Typical applications include:

  • Railway construction machinery and tunnel boring machines
  • Construction machinery in harsh outdoor environments
  • Modern entertainment and event technology, where loads are transported over people or people are moved.

By complying with the new Machinery Directive, TR Electronic already provides machine builders with the legal certainty that will be mandatory for future generations of equipment.

The SIL3 linear measurement system LM_I 46+FS at a glance:

Safety Highlights:

  • Certified safety: Full support for applications according to SIL3/PLe and SIL2/PLd
  • Redundant design: Two completely independent scanning systems in a single tube (2-in-1)
  • Future-proof: Compliant with the Cyber Resilience Act (CRA) and the new Machinery Regulation (MVO 2027)

General product features:

  • Scanning: Non-contact, wear-free, truly absolute, and with no system-imposed speed limit
  • Precision: High-precision resolution of 0.01 mm
  • Design: Available as a robust tubular version or a profile version

Connectivity & Protocols:

  • Interfaces: PROFIsafe via PROFINET (PROFIsafe address type 2)
  • Network Features: Fast Start-Up (FSU), Media Redundancy (MRP)
  • Profiles & Security: PNO Encoder Profile (KL 3/4) and PROFINET Security Class 1, System Redundancy S2 

Diagnostics & Integration:

  • Continuous signal monitoring (plausibility/quality) and internal hardware diagnostics
  • Separate, high-speed measurement channel for dynamic control
  • Secure preset interface and configuration via TCI Device Tool

Linear encoders from TR Electronic for SIL3 / PLe applications in our product selector 

Press article including photograph