The GX7016's Slot 1 is dedicated for the remote system controller. A PXI Star Trigger controller, any PXI or cPCI instrument or a GENASYS switching module can be used in slot 2. Slots 3-15 support the PXI Star Trigger, any PXI or cPCI instrument or a GENASYS switching module. Slots 16-20 accommodate a PXI or cPCI instruments without the Star Trigger or a GENASYS switching module.