Error -61073 When Using DMA FIFOs in LabVIEW FPGA

Issue Details

I am developing an application for my CompactRIO (cRIO) controller that acquires data from the FPGA and sends it to the Real-Time (RT) processor using a Direct Memory Access (DMA) FIFO. Additionally, I created a Host to Target FIFO that allows me to send data from the RT processor to the FPGA, so I have bidirectional communication. Even though I was able to compile my FPGA code successfully, whenever I try to write more than 10,000 elements to the Host to Target FIFO, error -61703 is generated:

Error -61073 occurred at FIFO.Write

Possible reason(s):

LabVIEW FPGA: The number or elements to read or write must be less than or equal to the depth of the host memory DMA FIFO

The error is presented in the following dialog box:

Solution

This error occurs when trying to write (or read) more samples than the actual configured depth of the host memory DMA FIFO.

By default, the size of the buffer used by the host FIFO is 10,000 elements or twice the size of the FPGA FIFO buffer, whichever is greater.

To resolve the error, try one of the options below:

• Reduce the number of elements being written to or read from the host FIFO to 10,000 elements or fewer.
• Increase the size of the host FIFO to accommodate more elements by using the FIFO.Configure invoke method, shown below. Before increasing the host FIFO size, ensure that sufficient memory is available on the host (RT target). To estimate the required memory, multiply the data type size (in bits) by the number of elements configured for the host FIFO.