Returns the number of supported simultaneous BLE connections.

        The BLED112 is capable of supporting up to 8 simultaneous BLE connections.
        However, the default firmware image has a limit of just 3 devices, which 
        is a lot easier to run up against. This method retrieves the current value
        of this setting. 

        Returns:
            int. The number of supported simultaneous connections, or -1 on error

def get_supported_connections(self):
        """Returns the number of supported simultaneous BLE connections.

        The BLED112 is capable of supporting up to 8 simultaneous BLE connections.
        However, the default firmware image has a limit of just 3 devices, which 
        is a lot easier to run up against. This method retrieves the current value
        of this setting. 

        Returns:
            int. The number of supported simultaneous connections, or -1 on error
        """
        if self.supported_connections != -1:
            return self.supported_connections
        
        if self.api is None:
            return -1

        self._set_state(self._STATE_DONGLE_COMMAND)
        self.api.ble_cmd_system_get_connections()
        self._wait_for_state(self._STATE_DONGLE_COMMAND)
        
        return self.supported_connections