Make sure the busy signal is set to active high polarity.
The LD_DATA_COUNT is recommended to be called in CNV_On stage.
Make sure the DMA Channel socket and the gpif thread number are matched. (For example, in your project if the dma channel from GPIF to USB used PIB_SOCKET_0, then in the settings of IN_DATA action, thread 0 should be selected and vice versa)
Please debug with the help of a oscilloscope in order to make sure the state machine transition takes place as expected.
I will test it again , Thank you. Madhu Sudhan.
I want to ask again a question, how do I transfer strings by SDI in GPIF II?