The Twincat IoT Communicator from Beckhoff enables communication between the PLC and a mobile device. It connects the 'Twincat' controller directly to a messaging service via secure TLS encryption. The associated 'IoT Communicator App' displays the process data clearly on the mobile device - be it a smartphone or tablet. Alarms are sent to the device via push notifications and the 'IoT Communicator' uses the publish/subscribe method to exchange data. No special firewall settings are required, which simplifies integration into an existing IT network. Information is exchanged via a message broker that uses the standardized MQTT protocol and acts as a central messaging service in a cloud or local network. The transmitted process data is displayed on the mobile device via the 'IoT Communicator App', which is available for both the iOS and Android operating systems. A QR code scanner is integrated into the app to make it easier to enter the access data for the broker and the respective user.