ni / ni/nidaqmx-python

Waveform timestamps do not have enough precision for high AI Convert Clock rates

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bug
Dominant language
Python
Stars
592
Forks
199
Avg merge
1d 16h
Merged PRs (30d)
10

Description

Bug Report

Waveform timestamps are returned from the DAQmx C API in .NET-style 100ns ticks, which is not high enough precision for high AI Convert Clock rates.

Repro or Code Sample

Add print(f"{time_offset:f}") to the updated voltage_acq_int_clk_plot_wfm.py from #940 and acquire Dev1/ai0:3 with a sample rate of 250e3.

Expected Behavior

Each channel has a unique time offset.

Current Behavior

Each channel has a time offset of 0.0.

0.000000
0.000000
0.000000
0.000000

Possible Solution

Fix internal bug AB#3229757

Context

Updating shipping example to plot multiple channels correctly

Your Environment

  • Operating system and version: Windows 11
  • NI-DAQmx version: 2026 Q2 dev build
  • nidaqmx-python version: 1.5.0 dev build
  • Python version: 3.11.7

AB#3782148

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the updated voltage_acq_int_clk_plot_wfm.py example from #940 and reproduce the Dev1/ai0:3 acquisition at a 250e3 sample rate, checking the printed time_offset values. Trace how waveform timestamps returned by the DAQmx C API are represented in Python, then use internal bug AB#3229757 as the reported implementation reference. Done means each channel has a unique time offset and the multi-channel plot is correct.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
api, backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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