A reader only decodes the symbologies that are enabled. Identify the code type first: EAN-13 and UPC-A in retail, Code 128 in logistics, QR and Data Matrix in 2D. Then enable it with the programming barcode from the manual. A laser reader will never read a 2D code, whatever the configuration.
Procedure
Identify the failing code’s symbology
A square with three corner markers is a QR code; a square without them is probably Data Matrix; vertical bars with 12 or 13 readable digits are UPC-A or EAN-13. Most of the rest is Code 128.
Confirm the reader is capable
A laser reader sweeps a line: no setting will make it decode a 2D code. If the failing code is a QR or Data Matrix and the reader is a laser model, replace it with an imager-based reader.
Enable the symbology from the manual
Each symbology has its own enabling barcode in the model’s manual. Enable only what the client needs: leaving every symbology active slows decoding and increases the risk of a misread.
Check the code’s print quality
A code printed too small, without a white quiet zone around it, or on a faded label will not read even with the right symbology. Compare against a cleanly printed sample before blaming the reader.
Test on several samples
A single label can simply be defective. Try several samples of the same code type, from different batches, before concluding. Write down what scans and what does not: the diagnosis starts there.
Check these before calling support
- The reader type (laser or imager) has been confirmed.
- The same code fails on several samples and on a second reader.
Useful terms
- Symbology
A symbology is the grammar of a barcode: which characters it accepts, how they are drawn and how they are checked.
- Code 128
Code 128 is a high-density linear symbology that encodes the 128 ASCII characters.
- EAN-13 and UPC-A
EAN-13 (13 digits) and UPC-A (12 digits) are the symbologies used for retail product codes.
- QR code
The QR code is a 2D matrix symbology recognizable by its three finder squares.
- 2D barcode
A 2D barcode is a matrix code that encodes information on two axes, in light and dark modules.
- Imager or laser reader
An imager-based reader is a reader that photographs the target and decodes both 1D and 2D codes, including on a phone screen.
Hardware involved
- SC310 (Barcode and card readers)