Alexander Melkus: "With Hot Swap, safety substations can be added, removed and regrouped almost at will during operation."

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With its S-Dias safety system, Sigmatek has always focused in particular on modular production machines and lines with optional modules such as loading and unloading units as well as handling and transport systems. The machine units are equipped with their own safety controller and communicate with the higher-level safety controller via the Varan industrial Ethernet. The safety-relevant signals are transmitted via Black Channel using any communication media. "With wired solutions, a single cable is sufficient for safety and standard communication. However, transmission can also be wireless, for example via WLAN," says Sigmatek Managing Director Alexander Melkus.

The hot-swap feature is new for SPS 2019. In future, it will ensure that the machine parts with their safety CPUs can be flexibly integrated into the system, logged off and logged on again at another point in the machine network - and all this at runtime. According to Melkus, the higher-level central safety controller is able to manage up to 70 optional substations with emergency stop function.

The overarching safety program is configured once with all possible participating units in the machine network and can subsequently be combined as required - just like the modular machine or line. This means that optional system modules with an integrated emergency stop function can be added to or removed from machines and systems during operation without the need for a restart. The dynamic connection is established via a simple, function-oriented log-on mechanism - without a hardware switch. Disconnection is triggered by a safe input. If a unit is disconnected from the central safety controller without first logging off, an emergency stop is triggered for all connected machine modules after the configurable watchdog time has elapsed.

In addition to the safety controller, the modular safety system in pocket format includes various safe I/Os and drives with safety functions. The 'Lasal SafetyDesigner' with its library of standard and safety function blocks, based on the PLCopen standard, makes it easy to configure the safety applications.