NI-XNET Signal Input Sessions Return Zero Values but Frames Are Recognized

Updated Mar 27, 2023

Reported In

Software

  • LabVIEW

Driver

  • NI-XNET

Issue Details

When trying to read incoming signals or frames using an Input Single-Point or Queued sessions, I observe that the frames received have an empty payload and the signals have zero as their value. 

Still, If I use a Frame Input Stream session instead I can see the correct values in the payload received. This issue happens both in LabVIEW and the NI-XNET Bus Monitor. 

Solution

This issue happens because the incoming frames have extended frame IDs and the database used to read the input is not configured to read extended frames. 

Although the frame IDs seem to be same, NI-XNET is capable of differentiating between extended IDs and standard IDs and will only return the frames that match the database settings. 

This could be fixed by editing the database and selecting the 29bit ID option in the NI-XNET Database Editor as shown in the image below. 

image.png
 

Other Support Options

Ask the NI Community

Collaborate with other users in our discussion forums



Request Support from an Engineer

A valid service agreement or active software subscription may be required, and support options vary by country.