Thank you for the response :),
all three checked (64bit os was okay, DLL was the same, no new information found for my ), but same issue.
In the VB-2010 example it's only a:
hUSBDevice = CreateFile(sPort, GENERIC_READ Or GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL Or FILE_FLAG_OVERLAPPED, 0) 'create handle (WIN32 API...)
CP210xRT_WriteLatch(hUSBDevice, &HF, &H0) ' Write new GPIO setting to switch the relays. 0F(hex) => all GPIOs will be addressed
CloseHandle(hUSBDevice)
in the "switch all 4 relay ON" button event
But same execution of DLL-function in SerialPudit doesn't work (except to set GPIO to High to deactivate Relays)
The DLL only provide write and read of the registers not to configure them as input/output, also no configation found in the VB-2010 example.