WTViewerFreePlus for WT300/WT300E Series

The WTViewerFreePlus software captures measured numeric values, harmonic values, and waveform data. Users can view and save data on a PC using USB, GPIB, RS-232, or Ethernet.

You can use WTViewerFreePlus to connect WT300 / WT300E series power meters (hereafter referred to as WT) to a PC and:

  • Retrieve, display, and save data that the WT has measured and setup parameters
  • Remotely control the WT

Setting Window

As well as using the WT300 / WT300E series front panel to set up the power meter, users can quickly set up preferred conditions. It also shows  setting parameters and status at a glance. For instance, you can set up the range-skip function (range-configuation setting) and specify the maximum order for the THD calculation.

SettingWindow LG

Measurement Window

The software can display items which cannot be shown on the display of the WT300 / WT300E series, such as multiple numeric measurement parameters, the harmonics data of each other, bar graphs, trend graphs, and voltage & current waveforms.

MeasurementWindow LG

Multiple units

  • WTViewerFreePlus can connect up to four WT300 / WT300E series units (with same model code).
  • The WT300 / WT300E series provides flexibility by offering various communication interfaces such as USB, Ethernet, GPIB and RS-232.
  • With the "Device Search" feature, the software allows automatic PC connection.
  • The software allows instrument configuration and measurement of up to 200 measurements simultaneously.


When the connection is established and the WT and PC are online, an illustration indicating this stage appears.

Software Menus

Connection: Communication configuration between WT and PC
Setting: Set up WT measurement parameters
Measure: Display measured results in bar graphs, trend graphs, etc.
File: Save and load setup parameters
Exit: Exit the software

Types of Display Screens

The following types of display screens are available.

  • Numeric
    Displays WT’s measurement data numerically. For models with the harmonic measurement option
    (/G5), harmonic measurement data is also displayed.
  • Numeric List
    Lists harmonic measurement data for each harmonic order.
    Numeric lists can be displayed when the WT is equipped with the harmonic measurement option
  • Numeric Matrix
    Displays WT’s measurement data for each element.
  • Waveform
    Displays waveform display data that has been collected from the WT.
    Waveforms can be displayed when the WT is equipped with the harmonic measurement option
  • Trend
    Displays changes in measured data over time on a trend graph.
  • Bar Graph
    Displays measured harmonic components for each harmonic order.
    Bar graphs can be displayed when the WT is equipped with the harmonic measurement option


Measuring Mode Normal, harmonics, integration
Types of Files Waveform, calculated values, harmonics, settings
Display Screens Numerical, waveform*, trend, harmonic Bar Graph*
* /G5option is required on .
Data Acquisition Interval 100 ms at max. speed.
- The data storage period can be any custom settings (more than 2 seconds) and the data update rate of the body.

- Depends on your PC's performance.*When the WT data update interval is shorter than the time it takes for the software to collect one set of measured data, there will be pieces of data that the software will not collect.

System Requirements

PC CPU Pentium 4 1.5 GHz or faster recommended
Memory 2 GB or more recommended
HDD 1 GB free space or more
Operating System English version of Microsoft Windows XP (SP3 or later)1, Windows Vista 1 or Windows 7 2
1 32-bit versions are supported.
2 32-bit versions and 64-bit versions are supported.
Communication Board GP-IB NI (National Instruments)
1 NI-488.2 driver Ver. 1.60 or later (except Ver. 2.3)
2 Not supported on Windows Vista or Windows 7
3 Use driver NI-488.2M Ver. 2.8.1 or later.
RS-232 An available PC COM port
Ethernet An Ethernet port that supports 10BASE-T or 100BASE-TX
USB A USB port that supports USB Revision 1.1 or higher
Display, Printer, and Mouse Screen Resolution 1024×768 dots or higher
Operating System Operating system mentioned above

List of functions

Display Numeric Data Display Available
Waveform Display Available
Trend Display Available
Harmonic Bar Display Available
Vector Graph Display Function N.A.
X-Y Display N.A.
Display From the PC Available
Types of Files Conversion to CSV Available
Data Acquisition Interval 100 ms at max. speed. Available

The WTViewerFreePlus is  a free software including the IM CD.
It can detect connected WT300 series automatically and there are dedicated Setting page and Measurement page separately.

Setting page

Data displaying page


Max. order setting of THD calculation

Range skip (configuration) setting

Multi-Language Support


Looking for more information on our people, technology and solutions?

Contact Us

Precision Making