Implement new machine concepts flexibly and fast

Implement new machine concepts flexibly and fast
Modular safety system up to PL e/SIL 3
Published: 27 May 2020 - 9:11 a.m.
By: Staff writer

The machine building sector must also be able to react flexibly and fast. Therefore, Phoenix Contact has launched PSRmodular, a new safety system that can be easily adapted to new general conditions and that is versatile in application – and with maximum safety up to PL e and SIL 3.

Chameleons react to changes in their environment with minimum delay – by changing color. They do this through tiny crystal cells located in their skin. In today’s industrial production environment, it is also necessary to be able to meet specific customer demands flexibly and fast. In the special-purpose machine building sector in particular, it is often the case that machine concepts must be adapted to individual requirements. The safety concept must be adapted in turn. In order to achieve the necessary SIL (safety integrity level) or PL (performance level), the safety-related parts of the safety equipment and control devices must also operate correctly so the system can remain in the safe state or enter a safe state in the event of of failure.

Up to 160 safe I/Os can be integrated

Experience shows that functional safety requirements become more stringent as the level of automation increases. Different safety functions such as emergency stops, safety door interlocking systems, light grids, or pressure-sensitive mats that depend on different operating modes must be linked together, for example. With the modular safety system of the PSRmodular product family, applications up to PL e (EN ISO 13849) and SIL 3 (IEC 61508, respectively EN 62061) can be realized. The system uses TBUS DIN rail connectors, which means that users can flexibly adapt and extend it in accordance with their individual requirements. This means that the solution can be used for everything from small applications with three safety functions to applications, right up to applications with 160 safe I/Os in one station.

The comprehensive portfolio contains various functional modules based on the proven MEmax housing concept and an overall width of only 22.5 millimeters. The modules are available with screw or Push-in connection technology as required. In both cases, tool-free installation cuts down on commissioning time. Two basic modules with different performance ratings form the heart of the system. They support safety-related communication with each other. With this technology, classical use cases such as line-emergency stop concepts for production plants are easy to implement.

Reliable evaluation of various encoder signals …

In addition to the monitoring of classical digital signals, modules for reliable motion detection that can evaluate different encoder signals such as proximity switches, TTL, HTL, or SIN/COS are available. The function block library encompasses safety functions in accordance with IEC 61800-5-2 such as safe operation stop (SOS), safe limited speed (SLS), safe speed range (SSR), and safe direction (SDI). Therefore, the speed of the spindle in machine tools and wood processing machines can be controlled during setup mode when the safety equipment is open, for example. If the application exceeds the preset speed due to an error in the drive system, creating a hazard for the operator, the drive immediately shuts off. PSRmodular is also ideally suited for use in wind turbine generators, whereby the modules can be used to monitor the rotor speed. In addition, they can be used in mobile applications such as driverless transport systems or logistics systems – so-called automated storage and retrieval systems – to control their speed.

In particular in extensive plants with distributed I/Os, a proven means of reducing installation work has been to wire sensors and actuators separately from the actual base module. A special extension module can be used for this purpose. It physically separates the local bus of the PSRmodular system and uses a proprietary protocol to implement it on the decentral stations. In this way, users can set up five separate segments every 50 meters within one station.

… and acquisition of analog measured values

The product portfolio is rounded out by a safe analog module for acquiring and processing fill level, temperature, distance, pressure, and force data. To do this, the module provides four mutually independent channels for the 4…20 mA range or 0…10-V signals at a 16-bit resolution. The current measurement range is 0 to 25 mA, making it suitable for connecting encoder signals with standardized levels in accordance with NAMUR recommendation NE 43. The analog measured values can be scaled in numerical values with a random unit of measurement during configuration. Alongside the option of limit value and range monitoring, it is also possible to carry out calculations such as adding or subtracting numerical analog values. As a result, the processes in process engineering systems are safely and reliably controlled.

The modules are configured via the user-friendly PSRmodular software, which contains comprehensive functions and diagnostic options. After the graphical circuit diagram has been created, the configuration can be loaded to the module directly via USB connection. Alternatively, a pre-configured memory module can be attached to enable series machines to be commissioned quickly, even without a notebook. During machine acceptance, the integrated reporting function supports the individual calculation of response time.

The common bus protocols – Profinet, Ethernet/IP, Modbus/TCP, and EtherCAT – are available to forward the process data. Due to the function blocks’ diagnostics option, operators localize the cause of plant downtimes quickly and definitively.


Whether for a simple machine or a modular safety concept: With PSRmodular in conjunction with the PSrmini safety relay family, Phoenix Contact offers a complete solution for versatile use in machine and process applications.

Box text:

Comprehensive solution for control cabinets

The PSRmodular and PSRmini product families are part of COMPLETE line. COMPLETE line is a system comprising technologically leading and coordinated hardware and software products, services, and system solutions intended to optimize processes in control cabinet manufacturing. Alongside functional safety technology, the COMPLETE line portfolio includes controllers and I/O systems, power supplies and device circuit breakers, terminal blocks and distribution blocks, relay modules and motor starters, signal conditioners, functional safety technology, surge protection, and heavy-duty connectors (Fig. 5).

COMPLETE line is characterized by the following features:

  • Intuitive handling, thanks to the uniform design, haptics, and function
  • Time savings throughout the entire engineering process with comprehensive software support
  • Reduced inventory costs with standardized accessories and reduced variety of parts
  • Improved processes in control cabinet manufacturing due to customized services and innovative manufacturing solutions

More information:

Dipl.-Ing. (FH) Carsten Gregorius, Senior Safety Specialist in the Automation Infrastructure Business Division, Phoenix Contact Electronics GmbH, Bad Pyrmont, Germany

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