Wrong label or allergen panel after changeover
The last run's label or film is still on the line. See Food, Beverage and Packaging.
Barcode inspection that catches the wrong label before it ships.
Every pack checked for the right label, a readable barcode, and the right date and lot for the order you are running.
Problems
What this station catches.
Wrong, unreadable, or low-grade barcodes
Every code is read, graded inline, and matched to the order. See Packaging.
Date and lot codes
The printer smudges or skips the code, or prints last run's lot. See Packaging.
Pharma label and leaflet against the batch
Each carton is checked before it leaves the cartoner. See Pharmaceutical.
Round parts in any orientation
Syringes, tubes, vials and round bottles arrive turned any way. See Medical devices and Pharmaceutical.
Packaging material checked before use
Wrong film, carton, can or label stock loaded at changeover is caught before the run starts. See Food.
Barcode inspection
What does a barcode inspection system check?
Every pack, at line speed: is the code there, can it be read, and is it the right one?
1D barcodes
UPC, EAN and GS1-128
Linear codes on labels, cartons and cases are read and matched to the product running.
2D codes
Data Matrix and QR
2D codes are read, and GS1 fields such as lot, expiry and serial are split out and checked.
Print quality
Print quality on each read
The reader grades print quality on each read using ISO 15415 and 15416 methods, so a printer that is drifting shows up before its codes stop reading.
Text
Date and lot with OCR and OCV
OCR reads the printed date and lot. OCV checks the text against the value expected for the order.
Defects
Which barcode faults does it catch, and why do they happen?
No read
The code is missing or unreadable
A missing label, a code outside the view, glare on film, or print too light to decode.
Wrong code
It reads, but it is the wrong product
A readable code for another SKU, usually left over from the last run after a changeover.
Poor print
Low contrast, smears and voids
A worn printhead, ribbon or ink trouble, or a label stock the printer was not set up for.
Damage
Wrinkled, scuffed or curved codes
Labels wrinkled when applied, scuffed in handling, or printed across a seam or a tight curve.
How it works
How the station reads.
Inline reader
Reads and grades every code at line speed, and rejects or holds when a code fails.
Offline verifier
Grades print quality off the line. Many plants use both: the verifier for the formal grade, the inline reader for every pack.
OCR
Reads the printed text.
OCV
Checks the printed text against the expected text. Date and lot checks use OCV because the expected value is known.
Setup
How are the camera and the light set up?
The pack, the code size and the line speed decide the setup. These are the choices the study makes.
Field of view
Enough pixels on the smallest bar
The camera has to see every place the code can land, with enough pixels across the smallest bar or cell to read it every time. The imaging calculator shows the trade-off.
Lighting
Light that matches the surface
Diffuse or dome light for glossy film and curved packs, low-angle light for marks on metal or plastic, and polarizing filters against glare.
Hardware
Fixed readers or GigE Vision cameras
A fixed-mount reader covers one face. For several faces or a wide view, GigE Vision cameras feed a vision controller.
Line
Trigger, PLC and reject
A photo eye triggers the read, the result goes to the PLC, and a failed pack is rejected when it reaches the reject.
Line speed
What changes as the line gets faster?
Motion
Freeze the code
A short exposure and strobed light keep the bars sharp on a moving pack.
Orientation
Packs that arrive turned
Packs turned any way need omnidirectional reading or more than one reader. A barcode tunnel reads cases from several sides.
Decode time
Finish before the next pack
Each read has to finish before the next pack arrives. Dense 2D codes and many codes per pack take longer, so the study tests them at your speed.
Spacing
A gap between packs
Packs that touch can be seen as one. The gap and the trigger position decide which pack a result belongs to.
Limits
What can’t a barcode inspection system catch?
Upstream data
The wrong expected value
If the printer template or the product setup holds the wrong data, a code can read and match the wrong value. The check is only as good as the value it is given.
Formal grade
A grade for a customer report
Inline grades show trends on every pack. A formal print grade comes from an offline verifier set up for it.
Hidden codes
A code no camera can see
A code under an overwrap, folded into a seam or facing away from every reader is a no read, not a pass.
FAQ
Questions about barcode inspection
QWhat is the difference between a barcode reader and a barcode verifier?
An inline reader reads and grades every code at line speed, and rejects or holds a pack when a code fails. An offline verifier grades print quality off the line for the formal grade. Many plants use both.
QCan it check that the barcode matches the product running?
Yes. The expected code is set for the product running. A pack whose code reads but does not match is rejected or held, the same as a pack with no read.
QDoes it read 2D codes such as Data Matrix?
Yes. 2D codes such as Data Matrix and QR are read along with 1D barcodes. GS1 codes are split into their fields, such as the product number, lot, expiry and serial, so each field can be checked.
QWhat happens when a code cannot be read?
A no read counts as a fail, never as a pass. The pack is rejected, or the line holds, depending on how the station is wired to your PLC.
Every JM station is handed over with the same documents, test and training. See what is handed over at site acceptance.