Hi Travis,
thanks for the fast answer 
For the pictures above, I have tried with a managed router. As the Test Box I am developing limits my hardware space, I would prefer a direct connection to the mini PC in the Test Box.
Out of interest: why it would work with a unmanaged switch but not with a direct connection to the PC.
Iām gonna look for an unmanaged switch and will test it.
I have more Test Setups in planning. So if it gonna work well, I will purchase some more industrial relay cards 
Best regards
Minh
P.S.: The description mentions a direct connection to the PC if I use the jumper. I thought after setting a static IP I could also control a board via a direct connection with a PC. Are my settings mentioned above not OK ? (wrong gateway maybe or so?)
