The REX 100 industrial routers from Systeme Helmholz can be snapped onto standard top-hat rails in the control cabinet. The router can be used to access Ethernet devices such as PLCs, regardless of the manufacturer. Variants for the 3G (GSM) or WAN (DSL) transmission standards are currently available on the connection side. The Ethernet version of the router is equipped with a 3-port switch, the mobile radio version with a 4-port switch. The model series is designed for operation in conjunction with the "myRex24" VPN portal: Programming and remote maintenance are carried out exclusively via the portal. Data transmission takes place via encrypted VPN tunnels based on the secure OpenVPN protocol. The routers have digital inputs, one of which serves as a trigger for establishing a connection to the portal server, while another can be assigned an alarm function. This means that routers with this function can send alarm text messages and e-mails; the data packets are forwarded directly to the automation network. Thanks to the "shSMS Wake-up" trigger function, it is no longer necessary to send an SMS or press the "Dial Out" button to initiate the connection to myRex24 on mobile routers. The portal sends the SMS automatically via shSMS to the stored mobile phone number. The previously selected router then connects to the portal.