The GSM interface transmits the alarm messages by SMS, control centre protocol or voice announcement via the mobile phone network. A separate voice module transmits the voice messages. In the event of an alarm or a fault, the GSM interface transmits the information that you have predefined. In combination with a voice module (AZ6451) you can also take up and transmit voice messages with a duration of 10 seconds each using the GSM interface. As well as the 4 alarm inputs, the GSM interface has 4 switch outputs: