C interface Funtcion cannot write an array to Labview

Hi

I have developed an vi in labview2012, and used the C Interface to convert the vi into api which can be used in Labwindows\CVI.

However, when I use the function NiFpga_WriteArrayU8, I cannot transport the array to labview. Can anyone help me?

I use the funtion in this way:

NiFpga_WriteArrayU8(session,NiFpga_Card4_SPI_ControlArrayU8_ArrayTx_SPI1, WriteData,1) 

NiFpga_Card4_SPI_ControlArrayU8_ArrayTx_SPI1 is the control ID in Labview

WriteData is an pointer which point to an unsigned char array .

Looking forward for reply.

michael