Selecting a single device/platform

[Snoopy]

I've got Device #1 and Device #2 on platform #1.

Wishing only to use device #2 for an attack.

appending the following hasn't worked:

-d 2
-D 1 -d 2
-d 1,2
-d 2,1

Does anyone know the correct command to only use the second GPU?

Thanks

without knowing your real setup

-D1 -d2 should do the trick, the lower -d refers to the device id, but to be sure, please show your output of hashcat -I