Error -1074100508: Stream Experienced Unhandled Interruption in NI FlexRIO High Speed Serial Module

Issue Details

I am using NI PXIe-6593 housed in PXIe-1071 in a simple loopback using QSFP28 cables. When running the default NI shipping example project from NI Example Finder, the ‘Continuous Stream Writer’ VI (i.e., Tx end) works. However, I face the following error when running ‘Finite Stream Reader’ VI (i.e., Rx end).

Error -1074100508:
Stream experienced an unhandled interruption due to a buffer underflow or overflow. Your transfer may be truncated

 

Solution

The PXIe-1071 has a PCIe x4 link between each of its peripheral slots and the controller which limits its throughput. During the receive (Rx), the FPGA target-to-host FIFO tries to push more data than the bus can sustain. Though the stream is finite, the instantaneous data rate increases beyond its limit causing this error.

Here are some of the possible solutions:

1. Use PXIe chassis with better backplane throughputs.
2. On the “Finite Stream Reader” VI, use small values for “Total Samples to Transfer” and “Samples per Read”.
3. Increase the FPGA Target-to-Host FIFO buffer size via internal and external (to FPGA) memories, e.g. DRAM. This solution is particularly helpful for finite streaming where the amount of data cannot be reduced.

Additional Information

• Please note that for best performance, NI PXIe-6593 and NI PXIe-6594 should be used in a chassis with a 58W cooling capacity.
• DRAM using memory instrument design libraries (IDLs) can also be leveraged to increase the FPGA FIFO buffer size if required. Please find “Getting Started – External Memory.lvproj” in NI Example Finder to understand different ways of DRAM usage.