Error -1073807339 Occurred at Visa Read

[VonBeks]

Hi Everyone,

Please find my code (Test.vi) and the error I am getting (09 - LabView Error.png) attached.

Basically the code writes and reads data to and from an FPGA using a serial port.

Once communication is established with the FPGA, you must 1st send 0xAA. There after you send 0xB1, 0xFF to read and output all its RAM data (8192 bytes).

I have tried the above commands out using RealTerm application and it works very well without any issues.  Please find RealTerm configuration and result files attached.

I am using LabView 2021. When I run the code in Labview, I get the above stated error.

I have used a picoscope to compare the signals being sent out by LV and Real Term and they are the same.

I have also tried to implement some of the ideas found in the LV examples and in the discussions here: https://forums.ni.com/t5/LabVIEW/Problem-with-VISA-Read/td-p/3812605

The Serial port of the FPGA has the following parameters: 

Stop Bit: 1

Data bits: 8

Flow control: None

Parity: None

At the moment, there is no data in the FPGA RAM so you get Zeros out as per the RealTerm's result screenshot

I have looked in NIMAX to see if I can use Test Panels to test the FPGA serial port but there is none for the device as per the NIMAX screen shots. All you get when you right click on it is a "Rename" option. Probably because its not an NI device?

Thank you for any assistance please.

Thank you