Free software for scales and balances with RS-232 and USB

Are you still manually entering weight readings from your scale or balance on your PC? Is your scale equipped with a RS-232 or USB (virtual COM port) interface? If yes, you can eliminate manual data entry by connecting your scale to your computer and using our free software 232key.

232key automatically types the weight into any application

Our software runs in the background, listens to the COM port (serial port) your scale is connected to and waits for measurement values sent by the scale. Those values are then filtered, formatted and typed into the application running in the foreground at the current cursor position as simulated keystrokes. This means that 232key can be used to transfer the weight (or other measurement values) into any application that accepts keyboard inputs, e.g. Microsoft Excel, OpenOffice / LibreOffice Calc, Google Docs, a form on a website, etc.

In the following example, I used A&D’s FG-60KBM scale with an optional RS-232 interface (FG-OP-23). I connected it to my laptop with A&D’s serial cable (AX-PC09-SCA) and an inexpensive converter to USB (as my laptop doesn’t have a serial port). Upon pressing the “PRINT” key on the scale, the weight was typed directly into an input field on a website:
Transferring the weight from a scale to a website

Compatibility with scales and balances

To use 232key, you’ll need a scale with a RS-232 interface (aka. serial port, COM port, EIA-232) or an interface which appears as a (virtual) COM port when the scale is connected to your PC. This is the case for many (but not all) scales with a USB interface and for scales which support the Bluetooth Serial Port Profile.

Your scale or balance also has to send the weight in ASCII format. The weight has to be the first numeric value sent* and it should only be sent once (after you’ve pressed a key on the scale), not continuously.

The vast majority of scales and balances available on the market today fulfills these requirements. Just to give you a few examples, you should be able to use 232key with most or all scales and balances made by A&D (RS-232 only), Adam Equipment (RS-232 and USB), Ohaus** (RS-232 and USB), Kern**, MyWeigh (RS-232 only) and other well-known brands. New device profiles are constantly added!

Finally, an easy way to transfer data from your scale to your PC

We designed 232key to make your life easier. No complicated configuration is required. If your scale manufacturer or model is included in the list of predefined devices, you don’t even have to manually enter the interface parameters: Simply select your scale and click on “Default” to load the settings.
Interface settings

Not sure which COM port you scale is connected to? Press the “Auto” button and 232key will try to detect the port automatically (works with all devices which have some sort of hardware handshaking functionality, e.g. scales and balances made by A&D and MyWeigh’s popular HD series).

Do you know which decimal separator (point or comma) your scale is using? Why should you! 232key understands both input formats and lets you choose which output format you want.
Decimal separator

Would you like 232key to press an additional key after typing the weight, e.g. the “Enter” key to jump to the next row in a spreadsheet? No problem, simply specify the desired key in the “Format” tab.
Additional key

All of these useful and user-friendly features are available for free! Additional functionality is available in the paid “Plus” version of 232key.

Download and documentation

Please visit our product website 232key for further information and to download our free software. Should you have any questions or suggestions, please don’t hesitate to post them in our support section or as a comment below.


* We’ve added an exception to this rule for scales and balances made by Adam Equipment.
** Affiliate links.

15 thoughts on “Free software for scales and balances with RS-232 and USB

  1. I am looking for a low-cost scale with serial output (USB or RS232) with which I can continuously log weight; for example, capture weight on the scale once a minute. The output of the scale can be monitored using a connected pc, perhaps using your software.
    The low cost scale should have a range of 0-25kg or 0-50kg, with a precision of at 1 g or better and accuracy of +/- 2% or better.

    We will be using the scale to monitor the rate of conversion of dry ice to gaseous CO2, in a protocol for measuring building ventilation rates.

    This is for educational use at a college in India, where funds are scarce.

    An recommendations?

  2. We slice smoked brisket, weigh it, and then pack it in a vacuum sealed bag. We need a way to export the weight of each pack and include it in a label that we print out

    Will your software do this with a suitable st of scales, a PC, and a printer?

    • 232key is a virtual keyboard wedge software designed to automate applications where the weight is currently being read from the scale by a user and then typed into an application running on a PC. This means that if you generate labels by manually entering the weight, you can use 232key to simplify this process. However, if you’re starting from scratch it might be better to either find a scale with an integrated label printer or a label printing application which can directly communicate with a connected scale (without the need for a virtual keyboard wedge).

  3. Will your software record the increase of weight on the scales as a function of time? I am looking to measure how fast a medium drains.

    • 232key is not meant to be a data recording (data logging) software, it just transfers the measurement values from a scale into whatever application currently has focus (cursor position). That said, if your scale has an interval mode to send the weight every x seconds, you might still be able to use it together with 232key for your application.

      We’re currently working on a dedicated data logging application, you can sign up to our newsletter to be informed of its release: http://www.simpledatalogger.com/

  4. I tried installing it but it says no rs232 comm port found on your system and then it exits. I do have usb port will that not work?

    • If your scale doesn’t have a print button, consult the manual to see if it supports automatic printing (on stability). Otherwise, you can unfortunately not use it with 232key at this time.

  5. Hello, thanks for the article. I need to scan ISBNS barcodes from books and weight them too, then input the data on our inventory panel on a pc with windows 10.
    do you have a solution for this? and which USB/BLUETOOTH/232 scale do you recommend in my case? can you mention one of each connection type?
    thank you.

    • I would get an USB barcode scanner, connect it directly to the PC and set it up so that it adds a tab after entering the ISBN. Then, get a scale which works with 232key* and configure 232key to send an enter key after the weight.

      With this configuration, you can create a spreadsheet, scan the ISBN and then weigh the book. The ISBN and weight will show up in the same row.

      *A list of supported devices can be found here: https://www.232key.com/documentation/index.html#device

      I particularly like the Ohaus Navigator series which can be equipped with an USB interface and supports automatic printing (so you wouldn’t have to press the print key on the scale).

  6. Thanks for the information. I’m looking for a simple solution. I have a scale that is USB and my computer only has USB ports. I simply need to put a package on the scale, have my UI read that weight from the scale and transfer that data to my UI. I might have the wrong that scale and all I’m finding as a solution is Download Stamps or Endicia software but they are wanting me to sign up.

    I wouldn’t think this would be a difficult problem to solve but I’m learning there’s not a plug and play solution out there. I plug in our bar code scanners, and it’s reads it and transmits it with ease. Do you have any suggestions?

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