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Transforms data received via RS-232 into keystrokes

Free RS-232 to keyboard software (keyboard wedge)

Use 232key to capture numeric values sent from a serial device and automatically enter them into any application as if you had typed them on the keyboard.

Our software captures data sent from a device connected to a serial port* of your PC and parses it to extract the first number**. This number is processed and formatted according to your requirements and typed it into any program as simulated keystrokes (virtual keyboard wedge). 232key can add an additional key at the end (e.g. the "enter" key to jump to the next row in a spreadsheet).

*Also called RS-232, EIA-232 or COM port. 232key also works with virtual COM ports (RS-232 to USB converter as shown in photo below, Bluetooth Serial Port Profile, serial over Ethernet, etc.).

**Since version 1.09, 232key also has basic support for alphanumeric barcodes (characters A-Z and digits 0-9).

Examples of devices which may have serial connectivity: measurement instruments (scales and balances, digital calipers, etc.), microcontrollers, sensors, barcode readers.

Perfect for balances and scales

Counting scale connected to a computer

In this application example, we used a counting scale to count the LEDs and pressed the "Print" key on the scale. Running in the background, 232key typed the quantity directly into a Google Docs spreadsheet:
Counting scale communicating with spreadsheet

You can use 232key with any software that accepts keyboard inputs (not just spreadsheets) and any device that sends numeric values in ASCII format.

Easy to use with exceptional features

232key software keyboard wedge for RS-232 and USB

Setup in just 6 steps

  1. Connect your device to your PC.
  2. Choose correct port and other connection parameters in the interface tab.
  3. Choose desired output format in format tab.
  4. Press start button in start/stop tab.
  5. Switch to target program (while 232key runs in the background) and place cursor where you want 232key to type the value.
  6. Press data transmission key on your device (usually labeled print or data) to transfer data. 232key types the formatted data at the current cursor position.

Steps 1 to 3 have to be completed only once, all settings are saved and loaded automatically. See documentation for further information.

Advanced support for scales and balances from A&D

RS-232 cable disconnected

Thanks to A&D's ingenious use of the handshaking lines, 232key can automatically detect the following errors and alert the user:

  • Scale is either not connected to the selected port or cable has been disconnected.
  • Scale is powered off or wrong type of cable is being used (null modem instead of straight cable).

These advanced error detection functions are only available when 232key is used with a scale or balance from A&D. See documentation (error messages) for further details.


  • Data sent by your device has to be in ASCII format.
  • 232key ignores any non-numerical data and extracts only the first decimal number in each line.
  • 232key cannot send commands to the device (unidirectional communication only).
  • You can only run one instance of 232key at a time and 232key can only connect to one device at a time.
  • 232key should not be used for data acquisition by itself. It is meant to run in the background while the data is written (typed) into another program.

Comments or questions?

Don't hesitate to ask a question on the FAQ page or to contact us.

Download RS-232 freewareDownload 232key

Click here to download 232key 1.62 for Windows.

Alternate download location.

By downloading, you agree to our EULA.

232key Plus license

The basic functionality of 232key is available for free. If you want to use the Plus features, please click here to buy a license for $29 or 27€ (including VAT, where applicable). Your license key and invoice will be generated immediately as soon as your payment is completed.

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