FIFO.Read (Invoke Method)

Reads elements of the DMA FIFO from the host memory part of the FIFO. The Read method returns Data when the Number of Elements is available. If the Timeout period ends before the Number of Elements is available, Data is empty.

Note The Read method is available only if the FIFO Type is Target to Host—DMA in the General FIFO Properties page.

Use the Invoke Method function to implement this method.

Option Description
FPGA VI Reference In FPGA VI Reference In is a reference to an FPGA VI. You must open a reference to the FPGA VI to use this parameter.
error in error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
Number of Elements Number of Elements determines the number of elements you read from the DMA FIFO.
Timeout (ms) Timeout (ms) specifies the minimum number of milliseconds the Invoke Method function waits before timing out. The Invoke Method function times out if the data is not available for reading by the time the number of milliseconds you specify elapse. The default is 5000 milliseconds. Set this parameter to –1 if you want the Invoke Method function to wait indefinitely.
FPGA VI Reference Out FPGA VI Reference Out returns a reference to an FPGA VI.
error out error out contains error information. This output provides standard error out functionality.
Data Data returns the data contained in the host memory part of the DMA FIFO. The number of elements contained in Data is either the same as Number of Elements or zero if the function times out.
Elements Remaining Elements Remaining returns the number of elements remaining that are available for reading.

The number of elements that this method returns is less than or equal to the actual number of elements remaining in the FIFO.