Free online LVM to XLSX converter

LabVIEW measurement results often need conversion when Excel, LibreOffice Calc, or a reporting system requires an editable workbook. Converting the data also makes it easier to filter, calculate, chart, and share measurements without LabVIEW.

What the LVM format is

LVM means LabVIEW Measurement File. National Instruments LabVIEW creates it through measurement-file VIs, including Write To Measurement File, for recorded channels, test results, and data-acquisition signals.

An LVM file is structured text rather than a spreadsheet. It normally contains a metadata header, an ***End_of_Header*** marker, and delimited measurement rows. The header can specify the field delimiter, decimal separator, time format, channel names, units, comments, writer and reader versions, and acquisition settings. A file can contain multiple measurement segments or groups, each with its own headings.

Because LVM is not merely a renamed CSV file, its header, delimiters, segment boundaries, and channel headings must be interpreted before the data is written to a workbook. A text editor can display the file but does not reliably convert its numeric and timestamp values.

What the XLSX format is

XLSX is the XML-based Microsoft Excel workbook format used by current Excel releases. It supports multiple worksheets, typed cells, formulas, tables, filters, charts, formatting, and workbook properties; LibreOffice Calc and other spreadsheet applications can also open it.

An XLSX workbook can keep measurements, copied LVM metadata, calculations, and charts on separate sheets. It does not automatically preserve every LabVIEW acquisition setting, original text representation, or multi-segment structure.

Using the built-in converter

1. Open the LVM-to-XLSX converter on 101convert.com.
2. Upload the .lvm file and select XLSX as the output format.
3. Start the conversion and download the generated workbook when it is ready.
4. Open the workbook in Excel or Calc and check the channel names, units, timestamps, segment boundaries, data-row count, and representative numeric values.

This option requires no installed conversion software and is free to use. 

Using Excel or Calc

1. Work from a copy of the original .lvm file.
2. In Excel, select Data → From Text/CSV. In Calc, use File → Open and open the file through the text-import dialog.
3. Choose the delimiter specified in the LVM header, commonly a tab or comma. Set the correct character encoding, decimal separator, and column types.
4. Preview timestamps, negative values, decimal numbers, empty fields, and scientific notation before importing.
5. If the file has multiple segments or repeated headings, import each segment separately or restructure them into separate worksheets. Copy useful header metadata to a dedicated worksheet.
6. Save with File → Save As and select Excel Workbook (*.xlsx) in Excel or Excel 2007–365 (*.xlsx) in Calc.

This is practical for a small, single-segment file. Renaming .lvm to .xlsx does not create a valid Excel workbook.

Using LabVIEW or DIAdem

LabVIEW can read LVM through the Read From Measurement File Express VI or related file-I/O functions. Separate the returned channel arrays, timestamps, and metadata, then write a delimited intermediate file with Write Delimited Spreadsheet File. Open that file in Excel or Calc and save it as XLSX.

For native workbook output, use the LabVIEW Report Generation Toolkit or another maintained Excel-reporting add-on where installed. Excel automation generally requires Microsoft Excel on Windows and should explicitly save in XLSX format.

NI DIAdem is useful for repeated test-data conversions. Load the LVM file, inspect channels, units, groups, and segments in the Data Portal, then use the version-specific export command. If the installation exports only CSV or another text format, open that output in Excel or Calc and save it as XLSX. DIAdem exporters and menu names vary by release.

Batch conversion with Python

For simple, single-segment files, install:

python -m pip install pandas openpyxl

The following example assumes that the first row after the header terminator contains column names and that the data is tab-delimited:

from io import StringIO
from pathlib import Path
import pandas as pd

source = Path("measurement.lvm")
target = Path("measurement.xlsx")
marker = "***End_of_Header***"
raw = source.read_text(encoding="utf-8", errors="replace")

if marker not in raw:
    raise ValueError("LVM header terminator not found")

_, data = raw.split(marker, 1)
frame = pd.read_csv(StringIO(data), sep="\t", header=0, engine="python")
frame.to_excel(target, index=False, sheet_name="Measurements")

Run it with python convert_lvm.py. Change sep="\t" to sep="," for comma-delimited data, and use decimal="," when the decimal mark is a comma. Inspect the header before automating: multiple segments, comments within the data area, repeated headings, unusual delimiters, or different encodings require a parser that processes each segment separately.

Quality and compatibility limits

• Copy units, comments, acquisition settings, and other header information to a worksheet or companion record; these values do not automatically become native XLSX metadata.
• Set field and decimal separators together. A comma decimal mark combined with comma-separated fields can split values incorrectly or import numbers as text.
• Excel supports a maximum of 1,048,576 rows and 16,384 columns per worksheet. Split larger acquisitions across sheets or retain the complete LVM as the archival source.
• Excel and Calc can reinterpret dates, timestamps, elapsed-time values, long integers, empty fields, and scientific notation. Compare row counts and representative values after conversion.
• Conversion is a data restructuring operation, not a guaranteed lossless copy of the acquisition file. Keep the original .lvm file beside the workbook, especially when segment boundaries, units, timing information, or acquisition settings matter.