INT32S DRV_FDIStart( PTR_T DeviceHandle, INT16U wCyclic, INT32U dwCount, VOID * pBuf );
On the device indicated by the DeviceHandle, it initiates the FDI (Fast Digital Input) functions by specifying the input count, the input data storage buffer, the cyclic mode etc.
This function can be implemented by calling the DRV_FDICheck.
This function is used in PCI-1755.
| Name | Direction | Range | Description |
| DeviceHandle | input | default | The pointer retrieved from the DRV_DeviceOpen which specifies the target device. |
| Cyclic | input | default |
0 - Non-cyclic mode; 1 - Cyclic mode. The buffer (pBuf) size depends on the hardware property and should be larger than half the FIFO size (FIFO of PCI-1755 is 32K bytes). |
| dwCount | input | default | The maximum data count the buffer can store. The count multiplied by the data size of each (Byte, Word or Double Word) is the buffer size. |
| pBuf | output | default | Pointer to the buffer
that stores FDI data. Needs to be initialized by the user. Since the FDI channels of PCI-1755 can be set to 8, 16 or 32 bits, the data format (data size of each), as concerned with the FDI channel number setting, can be byte, word or double word. Please refer to the Hardware Manual for details. At the same time, the buffer will be divided into two halves to support the loading and the output respectively. The user needs to call the DRV_FDICheck to check whether the first half or the second half of the buffer is vacant and to transfer data in time in order to avoid data overflow. To stop the operation, the DRV_FDIStop must be called. The first half and the second half of the buffer are equal; therefore, the dividing number is dwCount/2. However, if the user sets the data count (dwCount) to an odd number, the first half of the buffer will be larger than the second half and the dividing number will be (dwCount+1)/2. |
| 1. SUCCESS | Successful. |
| 2. InvalidDeviceHandle | The DriverHandle is NULL. |
| 3. InvalidCountNumber | The data count (dwCount) is 0 (invalid). |
| 4.Other value | Please reference ErrorCodes |