DMA FIFO works with simulated I/O but not target FPGA

[joedowdle]

I am working on creating an FPGA project for use with VeriStand but to do some intermediate testing I created a VI on the host computer and have been trying to send to data to the target FPGA using DMA FIFO.  I have my FPGA main VI created from the VeriStand template generated using the interface I/O tools.

Now when I run the target and host VI on the development computer with simulated I/O everything works just fine.  When I select it to execute on the FPGA target the host VI sits and waits at the DMA FIFO write invoke method.  Using highlight execution you can see the data going into the Data input but then it just sits there and waits.  If you look at the RT VI the data I am sending never gets updated with the new data I am trying to send.  Now it will send the first set of data, meaning that everytime I start up both VIs the RT VI will refresh and show the current data from the Host VI.

Some more specifics about my DMA FIFO:

In properties it is set to "Host to Target - DMA" with 21 as the number of requested elements (I am trying to send 8 - U64 pieces of data) and data type is set to U64.  Everything else is default.

In the RT VI, I have one DMA FIFO used that is "Target to Host - DMA" but I never read it in my host. (I did add a read invoke method earlier but it didn't fix it so I removed it.)  I have the Host to Target DMA in a for loop iterated 8 times and putting the 8 values into an auto-indexing array. (An example of this is shown in the I/O interface tools that I mentioned before.)

I hope that's enough information to get some helpful responses.  I am stuck on this; I cannot seem to figure out why this is happening. Any ideas?

[joedowdle]

I fixed it.  It indeed was because I didn't have an invoke method to read the other FIFO DMA.  I must have had something else wrong before that caused it not to work.  Everything seems to be working fine now.

[Kevin_H.]

Great! Thanks for posting the solution!

[joedowdle]

No problem.  I try to make sure I do that so if someone else has the same problem they can find it.  It bugs me when I find a post with my problem and say it was fixed, but never mention what fixed it.