Application example
Serial numbers on PCBs
- Challenge
- Small laser-marked DataMatrix codes with low contrast.
- Setup
- High-resolution fixed reader, coaxial-style lighting, ~4 px per module.
- Result
- Stable reading at every board for full traceability.
Components · Identification
Smart Cameras & Code Readers
Code readers and smart cameras combine sensor, optics, lighting, processing and I/O in one compact device. They are the fastest way to add traceability, OCR and simple inspections to a line without a separate PC.
Đầu đọc mã và camera thông minh tích hợp cảm biến, ống kính, đèn, xử lý và I/O trong một thiết bị nhỏ gọn — giải pháp nhanh nhất cho truy xuất nguồn gốc và OCR.
How it works
Module size, quiet zone and pixels per module
A code is made of modules — the smallest bars or squares. To decode reliably, each module needs enough pixels: roughly 2 pixels for clean printed 1D codes, about 3 for printed 2D codes, and 4–5 or more for direct part marks on metal or plastic.
Every code needs a quiet zone — an empty margin around it — so the reader can find where the code starts. Labels printed too close to edges or graphics are a common cause of no-reads.
Direct part marks (dot-peen, laser-etched, ink-jet) have low contrast and irregular modules. DPM readers combine special lighting (low-angle, dome, coaxial) with robust decoding algorithms to read them.
Types
Device types in detail
Open each type for how it works, where it fits, its limitations and the specifications to check.
01 Fixed-mount 2D code readerCompact readers for 1D and 2D codes on production lines.
How it works. Integrated camera, lens, lighting and decoder. Outputs the decoded string and status to PLC or PC.
Best for
- Part and tray traceability
- Label reading at stations
- Line integration via industrial Ethernet or I/O
Limitations
- Field of view and focus range set by the model and lens
Key specs to check
- Resolution
- Field of view / reading distance
- Decode rate
- Lighting options
- Interfaces
02 DPM readerOptimized for codes marked directly on parts.
How it works. Special lighting (low-angle, diffuse, polarized) and decoding algorithms for dot-peen, laser-etched and ink-jet marks with low contrast.
Best for
- Automotive castings and machined parts
- Medical instruments
- Electronics with laser-marked codes
Limitations
- Small field of view for small marks
- Mark quality strongly affects read rate
Key specs to check
- Lighting modes
- Pixels per module supported
- Resolution
03 High-speed / wide-FOV readerReads codes on fast conveyors and large areas.
How it works. High-resolution sensors, fast decoding and wide optics; multiple readers form a tunnel to read codes in any orientation.
Best for
- Logistics sorting and shipping
- Carton and tote identification
Limitations
- Requires careful layout for multi-side reading
Key specs to check
- Conveyor speed supported
- Field of view width
- Depth of field
04 Industrial handheld readerRugged handheld scanners for manual stations.
How it works. Corded or wireless readers with DPM capability for rework, kitting and inspection stations.
Best for
- Manual assembly and rework
- Receiving and kitting
Limitations
- Depends on operator action
Key specs to check
- Drop and IP rating
- DPM support
- Wireless range
05 Smart cameraA complete vision system in one housing.
How it works. Camera, processor and vision tools (locate, measure, count, read, OCR, sometimes deep learning) configured with a graphical interface.
Best for
- Single-camera inspections
- Presence, position and assembly checks
- OCR of dates and lot numbers
Limitations
- Less processing power than a PC-based system
- One camera per device
Key specs to check
- Tool set
- Processing speed
- Resolution
- Optics and lighting options
06 Vision sensorSimple, low-cost checks with minimal setup.
How it works. Pre-configured tools for presence, color, contour or simple measurement — set up in minutes.
Best for
- Presence / absence
- Orientation checks
- Color mark detection
Limitations
- Limited flexibility for complex inspections
Key specs to check
- Detection modes
- Teach method
- Output types
07 Code verifierGrades code print quality, not just reads it.
How it works. Calibrated optics and lighting measure contrast, modulation, damage and other parameters and report a grade according to ISO/IEC methods for 1D, 2D and DPM codes.
Best for
- Proving marking quality to customers
- Detecting marker degradation early
- Process control of printers and lasers
Limitations
- Requires defined geometry and calibration
Key specs to check
- Supported standards
- Aperture sizes
- Calibration card
Compare
Common code types
| Code | Type | Typical use | Notes |
|---|---|---|---|
| Code 128 / Code 39 | 1D barcode | Labels, logistics, parts | Needs a long, wide quiet zone |
| EAN / UPC | 1D barcode | Retail products | Fixed length |
| DataMatrix (ECC200) | 2D matrix | Part marking, electronics, pharma | Very small sizes; robust error correction |
| QR code | 2D matrix | Packaging, consumer-facing labels | Large data capacity |
| PDF417 | Stacked 1D | Documents, ID labels | Needs good resolution horizontally |
| DPM (dot-peen, laser) | Marked 2D | Metal and plastic parts | Low contrast; needs special lighting |
Specifications
Key specifications explained
| Specification | What it means | How to choose |
|---|---|---|
| Resolution | Pixels of the reader's sensor. | Determines the smallest module at a given field of view. |
| Field of view & distance | Area covered at the reading distance. | Must cover code position tolerance with margin. |
| Focus type | Fixed, manual or electronic (liquid lens). | Electronic focus for varying distances. |
| Lighting | Built-in colors, diffuser, polarizer, external light support. | DPM and glossy labels need special modes. |
| Decode rate | Codes read per second. | Check against line speed and number of codes. |
| Supported codes | 1D, 2D, DPM, OCR. | Verify all symbologies used in your plant. |
| Interfaces | Industrial Ethernet, TCP/IP, serial, digital I/O. | Match your PLC and MES integration. |
| Housing | IP rating, temperature, size. | IP65/67 for wash-down or dusty areas. |
Engineering tools
Calculate before you choose
Quick estimates based on standard formulas. Always confirm with a test on real parts.
Code Reading Calculator
From the smallest module size and code type, estimate the maximum field of view for a reader resolution.
Selection guide
Which device for which task?
| Requirement | Recommended | Why / note |
|---|---|---|
| Printed labels on fast conveyors | High-speed wide-FOV reader (tunnel for any orientation) | Plan reading from several sides. |
| Laser or dot-peen marks on metal | DPM reader with low-angle or dome lighting | Test with real marked parts. |
| Tiny codes on PCBs | High-resolution reader with small field of view | Check pixels per module. |
| Parts at varying heights | Reader with liquid-lens autofocus | Or a reader with large depth of field. |
| Prove marking quality | Verifier with ISO/IEC grading | Use in process control. |
| Code + OCR + presence in one station | Smart camera | One device, several tools. |
| Simple presence or color check | Vision sensor | Fast setup, low cost. |
Selection steps
- List all code types, sizes and marking methods (label, laser, dot-peen, ink-jet).
- Measure the smallest module size and the code position tolerance.
- Calculate field of view and resolution (see calculator).
- Choose lighting: standard for labels, special for DPM and glossy surfaces.
- Plan mounting: tilt glossy codes 10–15° to avoid direct reflection.
- Define interfaces and data handling (PLC, MES, database).
- Test the read rate on real parts, including worst-case marks.
Examples
Typical application examples
Illustrative setups showing how the components are combined in practice.
Application example
Dot-peen codes on castings
- Challenge
- Rough cast surface and irregular dots.
- Setup
- DPM reader with low-angle lighting and DPM decoding.
- Result
- Dots stand out from the rough surface and are decoded reliably.
Application example
Carton labels in shipping
- Challenge
- Labels could be on any side and at any angle.
- Setup
- Multiple wide-FOV readers forming a reading tunnel.
- Result
- Every carton identified without manual orientation.
Common mistakes to avoid
- Too few pixels per module — the most common cause of low read rates.
- Ignoring the quiet zone around the code.
- Mounting the reader perpendicular to glossy labels, causing glare.
- Assuming every mark is readable — poor marking quality must be fixed at the source.
- No plan for no-reads: define what the line does when a code cannot be read.
FAQ
Frequently asked questions
Why tilt the reader?
A small tilt (about 10–15°) keeps the mirror reflection of the built-in light out of the lens on glossy labels and films.
What is the difference between a reader and a verifier?
A reader only decodes the code. A verifier measures print quality parameters and grades the code so you can control the marking process.
Can a smart camera replace a PC-based system?
For single-camera tasks with standard tools, yes. For many cameras, heavy processing or complex deep learning, a PC-based system is usually better.
What is OCR vs OCV?
OCR (optical character recognition) reads unknown text. OCV (optical character verification) checks that printed text matches the expected value and quality.
Which code is best for small parts?
DataMatrix is usually preferred: it is compact, readable at very small sizes and has strong error correction.
Continue exploring
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