Can't connect to round display only gauge

[Jonas_R]

So I got my self a vems round display only but I cannot get it to connect to my pc.

I connect the gauge to my seriel port on the pc but when I start vems tune nothing happens.

I can connect my ECU to the seriel port on the pc and everything works as it should.

I use a male to female cable but it straight through cable and not a null modem.

As far as I understand I need null modem cable between ecu and display right?

So does the gauge need seperate power on the blue and red wire?

Or maybe it is just dead.

Any suggestions?