now I've worked out an alternative solution to this problem.
I've given up calling DLL-APIs in Labview and given up using Cypress Dongle, instead I made my own "Dongle" which consists of PSOC4-BLE and MCP2200(USB to COM). My "Dongle" scans adv data and send them to PC via virtual COM(uart <-> usb <-> PC_COM).
It's much easier to operate COM in labview instead of calling DLL-APIs.
Hope this can help.