Solmio POS supports GS1 variable-measure EAN-13 barcodes that encode weight or price information directly inside the barcode. These are commonly used with weighing scales printing labels for products sold by weight (produce, meat, deli) and pre-packaged goods with variable weight or price.

How It Works

When scanned, the system checks:

- First digit must be 2

- Second digit (prefix) determines weight/price and decimal precision

- Barcode must be 13 digits (EAN-13)

Barcode Structure

2X PPPPPP DDDD C

Prefix (2 digits) + PLU (6 digits) + Data (4 digits) + Check digit (1 digit)

Prefix Types

Price prefixes (20–22):

20 = 2 decimals, 21 = 1 decimal, 22 = 0 decimals

Weight prefixes (23–25):

23 = 3 decimals, 24 = 2 decimals, 25 = 1 decimal

Product Setup

1. Configure the PLU code in Solmio backend. It must match digits 3–8 of the barcode.

2. Configure your scale to print EAN-13 codes with the correct prefix (recommended: 23 for weight).

Scan Behavior

Weight barcodes: product is added with scanned weight as quantity, price is calculated automatically.

Price barcodes: product is added with quantity 1 and barcode price overrides the configured product price.

Troubleshooting

- Verify barcode is exactly 13 digits and starts with 2

- Ensure product has matching PLU in Solmio

- Check scale prefix and decimal precision settings