PC can't get EP0 data

[laden]

Hi，i use the fx3 to set a data link between PC and FPGA. On the USB control center，0x01 0x03 0x81 0x83 bulk endpoint serve as data transmission in auto dma mode from GPIF-II to usb（fig-1），endpoint 0 work as command transmission channel。I use function CyU3PUsbSendEP0Data(dataLen,ep0Buf) （fig-2）to send back data ,use the controlendpoint class implementation Read(PUCHAR buf, LONG &len) (fig-3)on PC ,fx3 shows that fx3 ep0 has send the data successfully, but PC get a failure as shown fig-5. Has any invalid operation?HELP me,thx!

fig-1 (USB CONTROL CENTER )

fig-2(FX3 SDK EP0 send data code)

fig-3 (PC reading  ep0 data code)

fig-4 (fx3 uart print the statue of fx3 ep0 sending)

fig-5 ( print the status of PC ep0 data reading)