S55 : Ring/Call indicator via plug

[maulwurf]

Hello,

does someone know.

Is it possible to switch a relais or something else,
when a call is coming in ?

I want to switch on a extra heating in my car by calling the S55.

Therefor I need a signal line where I can control the relais.

Thanks in advance.

Best regards,
maulwurf

Hope my english wasn't so bad ;-)