A handheld that reads a paper label has not demonstrated that it can read a code marked directly into the part beneath that label. Before choosing a configuration, establish how the mark is made, what surface carries it and how the operator can present that surface. Keep the packaging-label task in the evaluation if the same person must perform both jobs.
Consider a maintenance store issuing a machined component. Its carton carries a printed identifier; the component has a small mark that remains after the carton is discarded. The operator needs the component identity for a repair record. This is an editorial illustration, not a customer deployment or an AIDC GO test. It shows why a convenient carton scan may answer the wrong purchasing question.
Identify the physical mark, not only the barcode format
The symbology describes the encoded pattern. The marking process describes how that pattern appears on the item. A Data Matrix on a white label and a Data Matrix marked on a metal component can carry similar-looking identifiers while presenting different optical conditions. Knowing that a specification lists a symbology does not settle the second task.
Zebra's DPM application brief describes marking methods that include laser etching, dot peening and ink marking. These are examples of processes, not interchangeable sample conditions. Use the actual part and the mark owner's process description when specifying the task. Source: Zebra, DPM scanning application brief
For the maintenance-store example, label the samples separately: carton label C, directly marked component P and the expected identifier for each. The application owner should say whether those identifiers are identical, related or intentionally different. Do not substitute the carton value for the part value merely because the carton is easier to read.
Start with the existing barcode label and scanner basics for common sample information. Add the marking process, part material and finish, mark location, accessible approach and the state in which the part reaches the operator. A photograph helps explain the geometry, but a printed photograph is not an equivalent optical sample of the physical part.
Separate decoding settings from the optical configuration
The word “DPM” in a menu or quotation needs a precise scope. It might describe a decoding setting, a specific scan-engine option or a dedicated product variant. Ask which of those is being proposed, and record the exact model, engine and software version used in the demonstration.
Zebra DataWedge 15.0 documents DPM illumination controls only for DPM product SKUs with DPM scan engines. Its separately documented DPM mode has a different scope and does not support external scanners or scanning accessories. This is a manufacturer-specific illustration of why a software label and an optical configuration must be checked separately. It does not establish an equivalent feature on any AIDC GO model. Source: DataWedge 15.0, Barcode Input, DPM controls
In that documentation, illumination choices address different marked surfaces. Do not turn one recommended angle, colour of illumination or mode into a universal setup instruction. Have the supplier identify the applicable control and demonstrate the proposed configuration with the supplied samples. Record adjustments instead of quietly discarding attempts made before the adjustment.
The practical choice may be to evaluate one configuration for both carton and part, or to keep different capture paths for the two stations. A single-device approach is useful only if it meets both tasks under their working conditions. The mobile computer versus barcode scanner guide addresses where the application runs; this evaluation establishes what the optical path must actually read.
Compare presentations the operator can reproduce
Place the component in its normal working position before demonstrating it. Can the operator rotate it safely, or is it held in a fixture? Is the mark on an accessible face or partly around a curved section? Does reading it require moving away from the screen used to confirm the job? These questions describe the permitted action, not a promised scanner capability.
Use the same identified part when comparing permitted approaches. If a supplier gets a read by lifting it into a new position, record that as a different presentation. Decide whether that action is practical at the station before accepting the result. Do not alter a part, apply a contrast material or change its surface finish without the responsible owner's approval.
The following comparison record is a suggested evaluation method. It contains no measured results or acceptance thresholds.
| Presentation | Record from the observation | Limits of this observation |
|---|---|---|
| Printed label on the carton | Returned value, label reference, device configuration and normal working position. | Does not establish that the mark on the component can be read. |
| Direct mark on the loose component | Exact part, mark process, surface state, permitted angle and returned value. | Does not establish reading when the same part is held in a fixture. |
| Direct mark in the working fixture | Accessible approach, any permitted repositioning and the result for that part. | Does not establish performance on a different finish or marking process. |
| Both tasks in the intended sequence | Carton value, component value and the application record selected at each step. | Does not establish that either value is correct without the expected-identity check. |
For the illustrated issue transaction, retain an expected value beside each observed value. Include a permitted negative case, such as a different component with its own known identifier. The receiving application must not treat “some code decoded” as confirmation that the requested part was issued.
Select representative variation with the mark owner: for example, parts from different documented finishes or the normal condition at the inspection station. Agree the number of samples, repetitions and allowed adjustments before the evaluation. This article supplies no universal read distance, minimum mark size or success-rate requirement.
Keep mark quality evidence separate from a reading result
If mark quality is in dispute, request the relevant assessment rather than trying progressively different readers until one decodes it. ISO/IEC 29158:2025 is a DPM symbol-quality test specification. Its public abstract describes changes to illumination, measurement and grading relative to the referenced symbol-quality methodology. It is not an AIDC GO device certification. Source: ISO/IEC 29158:2025, public abstract
Have the quality owner identify the applicable specification, edition and acceptance requirement. If a supplied report uses another edition, retain that information and ask whether it meets the project's requirements. Do not invent a mandatory grade or declare a report invalid solely from the date on its cover.
The scanning versus verification article explains why a decode and a quality report provide different evidence. Here the extra question is whether the report and demonstration concern the same physical mark and its relevant conditions. Neither proves that the application selected the right maintenance record.
Choose the next action from the remaining gap
If carton labels read but component marks remain unproven, keep the label result and leave the direct-mark requirement open. Request a suitable sample evaluation rather than assuming that a higher-priced configuration resolves it. If the mark reads only after an impractical movement, revisit the presentation or capture arrangement with the station owner.
If the optical result is satisfactory but the wrong record appears, take the identifier and application mapping to the software team. Keep that investigation separate from mark lighting. The manufacturing hardware page connects work-order and inspection tasks to the relevant device directions without assuming a particular MES interface.
For a hardware discussion, start with the handheld terminal category and supply the component samples alongside the ordinary labels the device must still read. Ask Integration & Support to identify the proposed model, configuration and available supporting documents. This article makes no claim that an AIDC GO configuration supports DPM, a particular marking method or a specified reading performance.
The purchasing outcome should identify which task has evidence, which presentation was used and what remains unresolved. That is a more useful basis for a shortlist than treating all two-dimensional symbols as the same optical job.