Can I Simultaneously Open FPGA VI References from Separate Host VIs?

Updated Jul 1, 2019

Reported In


  • PXI FPGA Module for FlexRIO
  • CompactRIO Controller


  • LabVIEW FPGA Module

Issue Details

If I have a VI running on my FPGA device, is it possible to have multiple host VIs accessing that VI? Or can only one FPGA VI reference be opened at any given time?


There is no locking mechanism built into the FPGA VI reference. This means that multiple Open FPGA VI Reference functions can be used from separate host VIs to connect to the same FPGA VI running on an FPGA device, however this is NOT recommended.  The reason this method is not recommended is that any FPGA host VI could write to the controls of the FPGA VI without notification to the other host VIs, and this could cause erroneous results/behavior in any of the other host VIs with open references to the FPGA VI.