Offset Issues When Logging Plug-in Data with Physical Channels in FlexLogger

Updated Oct 26, 2025

Reported In

Software

  • FlexLogger
  • FlexLogger Plug-In Development Kit

Issue Details

I have developed a plug-in for FlexLogger using the FlexLogger Plug-in Development Kit in LabVIEW. My plug-in retrieves data from the analog input channels of an NI Data Acquisition (DAQ) device, which is also connected to FlexLogger, and it executes some calculations, whose results are published on FlexLogger. Although my plug-in correctly calculates the output based on the received inputs, when I create a TDMS file in FlexLogger, the data being generated by the plug-in is not synchronized with the signals read by my DAQ device. There is an offset in the data generated by my plug-in, compared to the one being acquired by the DAQ hardware, as shown in the image below:

 

How can I synchronize the data being generated by my plug-in with the one coming from by my DAQ device in the TDMS file?

Solution

The offset observed in FlexLogger may be caused by not writing the data to the plug-in's channels with timestamps or timing information.  In the absence of timestamps, FlexLogger attempts to align the data as accurately as possible. However, in some cases, proper alignment may not be achievable, resulting in visible offsets. 

To solve the issue, write the data as waveform using the same t0 as the signals acquired from the NI DAQ device. This ensures consistent timing alignment across all channels. Please refer to the image below for more details:

 

Related Links

 

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.