The PSTN module has multiple uses:

• It enables the panel to communicate with a monitoring station (CMS) using common format protocols (SIA, Contact ID)
• For configuring a Voice ‘Follow Me’ over the PSTN with predefined recorded voice messages. If there is no voice module in the control panel, it’s also possible to set voice ‘Follow Me’ over the PSTN but it is limited for alarms – in case of an alarm the user receives a call, and on answering the call, hears beeps – these beeps are an indication of an alarm.
• When a voice module is installed, the PSTN module also supports incoming calls, including some remote operations through DTMF such as arming and disarming the system.
• The PSTN module can function as a primary communication channel to CMS and/or ‘Follow Me’, or as a backup communication in case of cloud failure.