Is there a limit to the number of variables a host controller can access on the PXI-7831R or PXI-7841R.

[bensteve]

What are the limitations on the number of variables that can be transfered between a PXI-7841R and the host controller?  For example, I have several software commands and status elements that the host controller uses to communicate with the PXI-7841R.  These elements are not dependant on the Digital or Analog I/O of the FPGA device.  Is there a limit?  Is there a speed specification for this communication (per number of I/O?).  Thank you.

[StephenB · Accepted solution]

Every control or indicator you create in your LV FPGA code allocates space on the Xilinx FPGA. As with all FPGA coding, there is no way to tell a 'hard limit' on space. As you add more controls and indicators, your compile will take longer and do different things to optimize where everything is stored on your FPGA. You can look at the compile report to see how much space you have left.

As far as the speed specification between the card and your host computer, that is going to just be the PCI specification speed of 133.3 MB/s - overhead.