Actually every Samsung TV with Ex-link port can be controlled via rs232 ( service port or not ) . Here's a part of discussion on that subject from a different forum :

" For the European Samsung models with a Service port instead of a ex-link port, direct RS232 doesn't work because the port is on TTL level.
You have to convert the RS232 control (which is 10-15V) to TTL level (3.3V).
Be aware that direct RS232 input in the Sevice port can damage the Service port!
More you can read at: [Link: wiki.samygo.tv]
There are several (cheap) converters, but the professional one is the B&B Electronics 232LPTTL33 (3.3V edition) (see attachment)
This converter is port powered and don't need a separate power supply and works perfect for us. "