No rs422 port available

I am using a Startech ICUSB422 USB/RS422 adapter. It is visible in OSX 12.6.1 but not in Nuendo 12.
I want to connect a JoeCo blackbox BBR1A but cannot seem to get it working. Midi is no option because as far as I know Nuendo does not support open loop midi. The Blackbox has only midi in.
Anyone with a similar situation?

I don’t understand your statement.
Nuendo is sending MIDI if you need to.

What is the idea behind the RS422 adapter?
It’s just a serial connection.

I use a Joeco BBR1A Blackbox which only has midi in. They use open loop mode. So I cannot get the MMC working. I also tried it with 9pin serial but Nuendo does not recognize the serial port and therefore not the device. My serial adapter is a Startech USB to 422 and in OSX 12.6.1 perfect visible.

I found this…

MMC should be possible.

Yes I know but serial does not work in my case on any device. Blackbox, Alesis HD24. Midi however works with the Tascam DA-98HR and Alesis HD24 bus not the blackbox. Tonight I am going to test the Fostex DV2424LV with serial 9 pin and midi.