seriesDashStyle

Specifies the line style of area series line.May be one of the llowing:
'Solid',
'ShortDash',
'ShortDot',
'ShortDashDot',
'ShortDashDotDot',
'Dot',
'Dash',
'LongDash',
'DashDot',
'LongDashDot',
'LongDashDotDot'

seriesSettings: {
    rangesplinearea: {
        seriesDashStyle: 'ShortDot'
    }
}

This setting is demonstrated in the following example.