Hacking Jura Coffe machine (Yet another ...)

Hi,

One day i woke up and had an idea to hack our Jura XJ9 coffe machine in our office. I know there is several projects in GitHub what has made successful to communicating with Jura coffe machines with Arduino board. Unfortunately none of them using XJ9 machine.

Still i decided to try some of those with my machine. And no luck so far. Jura machines have different maintenance ports, mine has DB-9. But as i have read it does not have regular RS-232 pinout but slightly remapped one and to make things even more complicated there seems to be at least 3 different mappings.

On top of that Jura uses somewhat wierd protocol for communication as well.

So far i have tried to several pinouts with several communication implementation samples from GitHub projects but no luck so far to be able to control machine from arduino.

So its time to dig deeper and go beyond trial end error - get to understand how things actually work inside jura controller.

It means there is two things what i have to make clear for myself. First pinout of DB-9 plug and second the protocol of communication.

So lets start with first one. What would be the easiest solution to find out Correct RX, TX and GND pins ?