Decentralized Muting of Electro-sensitive Protectice Equipment

Hybrid safety I/O module ensures an efficient flow of material and provides full safety functionality directly at the machine

Electro-sensitive protective equipment (ESPE) is used to prevent workers or objects from accidentally entering a hazardous area. If such an event occurs or if it is likely to occur, the system triggers an emergency stop of the machine. However, it must be possible to safely bypass (mute) the ESPE whenever a process-relevant object moves through the light curtains. This may, for example, be a dish container in the case of a semi-automatic cleaning system. To control both scenarios directly at the machine, Turck offers a system solution with decentralized safety functionality.

Your Benefits

  • Shorter time-to-market thanks to pre-tests of the modular safety application
  • Higher plant availability, since safety functions are controlled decentrally in single segments
  • IP67 protection and increased temperature range provide high flexibility when mounting the I/O modules 
  • IO-Link master ports allow users to expand the system to include additional safety elements

  • Only certain objects like this container may be fed to the cleaning system

  • Four inductive sensors in series detect the container on its way into the machine

  • Turck's safety I/O module guarantees a reliable muting of the ESPE – with decentralized intelligence

Four-zone muting with inductive sensors

Lining up four inductive sensors in series enables the electro-sensitive protective equipment to be muted by a properly fed container. If the first two proximity switches are damped, the safety light curtains do not trigger an emergency stop. As soon as the container has, however, been completely transported through the light curtain, and only the sensors in positions three and four are damped, the ESPE is active again.

Extended protection against manipulation

Additional protection against manipulation of the system can be provided by detecting the weight or height of containers. RFID technology is another option, with a read/write head identifying the tags of each container and transmitting trigger signals for the ESPE muting.

Safety I/O modules with IP67 protection

Coordinating the active and bypassed ESPE is a task for Turck's safety I/O modules TBPN (Profinet/Profisafe) or TBIP (CIP Safety) – either as a hybrid or full safety model. With the IP67 modules, users can implement all safety-relevant functions in the immediate vicinity of the hazardous area. Communication with a higher-level PLC is thereby maintained reliably, while the I/O module at the machine enables short cycle times.

Preliminary testing of functionality 

Thanks to the decentralized safety functionality of the block I/O modules, machine builders and integrators can perform system tests prior to commissioning. This eliminates the need for a costly on-site test procedure, especially when safety applications consist of many components.

Modularity increases reliability

Distributed intelligence enables modular system concepts. Advantages become apparent not only in a shorter time-to-market, but also in a higher plant availability. In the event of an unforeseen event such as a cable break, the safety functionality is retained in the unaffected areas.