LPN Design Guide

Ware's official design guide for LPN (License Plate Number) barcode and QR code tags in warehouses

Following the below instructions for barcodes or QR codes will help ensure Ware systems can scan and report on your inventory. The below standards also have the benefit of helping to future-proof your warehousing operation and allow for greater compatibility of different types of warehouse automation and robotic systems.

Introduction

There are two types of visual marks used by the Ware system, License Plate Numbers (LPNs), and our Navigation Markers. Ware provides you with the navigation markers which are applied to the fixed racking of your warehouse. The navigation markers are only used by our system as a kind of street sign to know where the drone is located. They use a special type of code specifically designed for robotics applications that you won't need to worry about as we'll print and ship those markers to you.

Your LPNs are applied to your inventory and are used by our system to uniquely identify that payload. These are what you'll see reported on in our portal. The system is capable of scanning a wide variety of 1-D and 2-D barcode types including CODE-128 and EAN. We recommend using a 2-D barcode such as QR-Code because they are more robust to detect and have built-in error correction. For example, a QR-Code with Level H error correction can have 30% of the barcode removed and still be readable.

Skip ahead:

--> QR codes here

--> Barcodes here

Ware LPN spec shown above, with both QR code and barcode

QR Codes

QR Specification

Regarding the QR-Code specification we provide, here are a few resources talking about the different types of QR-Codes. The 73x73 or 177x177 are also valid versions of QR-Codes (Versions 14 and 40 respectively). The number 21, 73, or 177 simply specifies the dimensions of the code in terms of the number of individual black and white boxes. Most free online generators hide these details and simply automatically scale up the version to fit the data that you've asked it to store.

Ware-recommended specification:

Symbol Version	Version 1 (21 x 21)
Error Correction	Level Q: 25% error can be corrected Level H: 30% error can be corrected (Preferred)
Size	2” - 3” square
Border	Allow a minimum ¼ inch border around the QR Code
Color	Black on White background

Total number of characters allowed

Error Correction	Numeric	Alphanumeric	Binary
L (7%)	41	25	17
M (15%)	34	20	14
Q (25%)	27	16	11
H (30%)	17	10	7

Version 1 (21 x 21) Data Type Maximum Lengths

Data Type Restrictions

Numeric:
- numbers 0-9
Alphanumeric:
- numbers 0-9
- uppercase letters A-Z
- Special Characters:
  - [Space]
  - $
  - %
  - *
  - +
  - -
  - .
  - /
  - :
Binary:
- ASCII Encoded Characters

Label Material

Non-glossy surface (matte)

LPN Application

Apply to a flat surface on the front-face (aisle-facing side) of the inventory
Avoid wrinkles
Do not wrap codes around the edges of boxes
Non-Issues:
- Orientation

- Location on pallet payload (as long as it's on the aisle-facing side)

https://en.wikipedia.org/wiki/QR_code#Design

https://www.qrcode.com/en/about/standards.html

https://www.morovia.com/free-online-barcode-generator/qrcode-maker.php - Barcode generator that allows specifying the version (21 x 21 - 1) and error correction level (H)

Barcodes

We typically see Code 128 barcode format and can recommend it.

The greatest factor in terms of compatibility with Ware is the individual width of each bar on the barcode.

We highly recommend an individual bar width of 1mm or greater.