Bind each accepted weight to the correct pack before printing. The interface must carry identity and status, not merely the latest number from the scale.
Checkweigher-linked print and apply systems use a weighing result to populate a label for a particular pack. The print engine does not weigh the pack or establish the validity of the measurement. Specify how the weighing system identifies a result, how the line tracks that pack and how the label controller knows that the result is suitable for printing.
Weigh-and-label architectures are used for variable-weight products, but the detailed integration depends on the equipment and process. The manufacturer example of a weighing and labelling module illustrates the architecture rather than a specification for a Lancing product. A live weight field is a separate scope item from a fixed nominal-weight label.
| Pack or job identity | Use a traceable reference or a validated position-tracking method. Define what happens if a pack is removed, added, stops or overtakes between weighing and labelling. |
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| Gross, tare and net | State which values the scale supplies and which system applies tare. Avoid subtracting tare twice or printing gross weight under a net-weight heading. |
| Units and decimal handling | Agree the unit, decimal precision, rounding and barcode field format. The displayed text, encoded data and source record should describe the same accepted value. |
| Measurement status | Define invalid, unstable, overload, underweight and overweight responses where relevant. An apparently numerical payload must not conceal an invalid status. |
| Quantity or price calculations | Assign the responsible system and approved rules. Do not assume the printer should calculate commercial values independently from the business or weighing system. |
| Release or reject state | Agree whether rejected packs are labelled, diverted before labelling or held. A rejected pack must not shift the next pack onto the wrong queued record. |
A useful commissioning test alternates clearly different known test records and pack presentations within the approved measurement procedure. The purpose is to expose a one-pack offset, stale value or incorrect queue response. Check the printed human-readable value and decoded barcode against the expected record for that physical pack.
These are integration checks, not a substitute for calibration, metrological assessment or the scale manufacturer’s acceptance procedure.
When measured weight is used for a trade transaction or regulated quantity declaration, do not assume that an ordinary process checkweigher is approved for that use. Confirm the applicable weighing-equipment and quantity requirements for the actual installation with the supplier and, where needed, Trading Standards or an approved verifier. GOV.UK weights and measures business guidance.
A successful barcode scan proves neither weighing accuracy nor legal suitability. Keep those acceptance criteria separate in the enquiry and quotation.
Only where the validated process guarantees that the latest value belongs to the pack being labelled and is valid for use. With multiple packs in flight, rejects or stop/start behaviour, that assumption is often insufficient. A controlled association and an explicit error response are safer requirements for the interface.
No. A nominal-weight label repeats a declared product quantity, while a variable-weight or catchweight record represents the relevant measurement for the individual pack. Specify which process you need before choosing the data source, label fields and checks.
The project must define that sequence. Suppress, cancel or reconcile the associated label job according to the physical reject arrangement. Confirm that the next accepted pack receives its own record rather than the rejected pack’s weight.
Provide the scale model and interface documentation, anonymised sample messages including fault statuses, pack spacing, distance to the label point, tare rules, label artwork and the required reject sequence. Include the intended use of the weight so measurement and trade requirements can be scoped correctly.
Technical references: Manufacturer example of a weigh-and-label architecture; GOV.UK: weights and measures business guidance. External references explain general principles; they are not specifications or availability statements for a Lancing machine.
Send the weighing interface and the actual conveyor sequence with the artwork. Lancing can review the labelling integration; the suitability and approval of the weighing system remain explicit project requirements.