The possibility to transmit safety-relevant signals over a standard bus system creates significant advantages in terms of planning, installation, operation, maintenance, diagnostics and costs.

The safety-relevant application is configured or programmed in TwinCAT software. This application is then transmitted over the bus system to a TwinSAFE Logic terminal. These logic terminals are at the heart of the TwinSAFE system. All safety devices  in an installation communicate with this logic terminal. Due to the enormous flexibility of the system, however, several TwinSAFE Logic terminals can be operated simultaneously in one network.

Communication via independent safety circuits

Communication between distributed TwinSAFE Logic terminals is very simple to implement with TwinCAT software. This applies not only to terminals in a network, but also to devices connected to different controllers. Safety-relevant data and signals can also be exchanged as soon as the controllers have established a communication connection via a fieldbus or via network variables. Of course, the response times and capabilities of the systems employed need to be considered.

For this purpose, TwinCAT software assumes the task of distributing the data. This central distribution of the data has two significant advantages:

• Since all safety-relevant data are fed via the functional controller, it can be used by the controller for diagnostic purposes. The generation of diagnostic data on the safety controller is not necessary. That saves programming effort as well as computing performance and thus costs.
• All fieldbus systems that are interoperable with TwinCAT software are also accessible to the safety equipment. The TwinSAFE/Safety over EtherCAT protocol is so safe that even heterogeneous fieldbus environments as well as the safety-relevant exchange of data between modules on different fieldbus systems are not a problem.

Certified safety function blocks and customising options facilitate configuration

The certified safety function blocks of the TwinSAFE Logic terminals allow the simple, error-free and inexpensive implementation of all safety tasks: from the simple monitoring of a safety door to complex muting functions based on digital signals and the safe control of highly complex process based on analog signals. It’s also possible to implement connected and daisy-chained systems in compliance with safety requirements. For this purpose, the so-called customising capability is especially useful: Within a safety application, safety-relevant subgroups can be formed. Subsequently they can be deactivated or passivated permanently or temporarily during ongoing operation. These are essential functions that are required to reliably operate networked safety systems. Without these functions, commissioning, maintenance and partial operation of linked machines is not possible or a highly complex task.

With the TwinSAFE Logic terminals, all diagnostic and status data of the function blocks can be merged into the cyclic EtherCAT telegram. In addition, diagnostic data are stored directly in the logic component to enable asynchronous access. Extensive diagnostics is thus easy to implement without additional application requirements.

A backup and restore mechanism facilitates exchange in the event of a fault

Since all parameters and settings as well as the application software are stored on TwinSAFE Logic components, the safety controller can be programmed either in the plant over the bus system or at the workstation and then simply plugged into the system.

The logic components provide a special backup and restore mechanism. Therefore, no additional exchangeable storage medium is required as in other systems. The user can activate this function in TwinCAT software or by the application.

If the original terminal has been exchanged, e.g. due to a defect, the system automatically recognises a new TwinSAFE Logic component and the valid TwinSAFE application is loaded automatically into the new terminal. The safety-related check takes place fully automatically and requires no intervention by the user. The maintenance staff only needs to exchange the Bus Terminal, everything else is accomplished reliably and securely by the TwinSAFE system.