INT32S DRV_FDOCheck( PTR_T DeviceHandle, INT32U * pdwStatus, INT32U * pdwRetrieved)
On the device indicated by the DeviceHandle, it retrieves the current status of the FDO (Fast Digital Output) function.
This function is used to check whether the data in the higher or lower part of the buffer is empty, in order to avoid buffer underrun.
This function is used in PCI-1755.
| Name | Direction | Range | Description |
| DeviceHandle | input | default | The handle retrieved from the DRV_DeviceOpen which specifies the target device. |
| pdwStatus | output | default | The current conversion status: bit0: running(1)/stopped(0), reflects whether the operation is running. It does not indicate whether the operation is normal or abnormal. bit4: underrun(1)/not underrun(0), indicates whether the data has not been loaded in time. If this occurs, the data may have been lost. bit9,8: not ready(00)/first half ready(10)/second half ready(11), indicates the buffer that needs loading data immediately. other bits: reserved. The DRV_ClearFlag can be used to clear the underrun status. |
| pdwRetrieved | output | default | The data count retrieved from the buffer. which indicates the output data count in the current buffer. Since the FDO channels of PCI-1755 can be set to 8, 16 or 32 bits, the data size of each depends on FDO channel configuration and the scale may be byte, word or double word. If the mode is set to cyclic when calling the DRV_FDOStart, this value will be clear to NULL after each circulation. When all data in the buffer has been transferred, this value will be the output data count (dwCount) configured by calling the DRV_FDOStart. |
| 1. SUCCESS | Successful. |
| 2. InvalidDriverHandle | The DeviceHandle is NULL. |
| 3. Other value | Please reference ErrorCodes |