With vb.net the communication did work fine, until I started a test program that showed that the port still was occupied by the first program (although that was properly closed). Tried a hot disconnect and reconnect and the problem was solved, until I tried to switch all relais off (at the start of the testprogram): that did give a memory error:
het lezen of schrijven van beveiligd geheugen. Dit duidt er vaak op dat ander
geheugen is beschadigd.
Velleman.Kits.K8090Native.SendCommand(IntPtr hDevice, Byte cmd, Byte mask, Byte
hparam, Byte lparam)
It looks like that part of the memory is damaged by the “hot disconnect” and reconnect. Is it possible to exchange the firmware chip for an undamaged one?