From the field

Reading DPM on tough metal parts at line speed

A low-contrast Data Matrix on machined metal may be readable on a clean, stationary part. On the line, oil film, limited visibility and part position change the reflected light and therefore the ability to decode the mark.

Context

An industrial manufacturer needed reliable Data Matrix reading on machined metal for product genealogy and process records. The integrator managed the cell I/O. A missed code could not be allowed to pass silently.

Why the bench test was not representative

Oil film, cutting marks, curved surfaces and parts that blocked part of the code from view changed the available contrast. Specular reflections could make a code unreadable even when it decoded under soft ambient light. Position variation between rows introduced another source of failure.

Production conditions

The trial had to cover the actual cycle time, restricted installation space and the required response to an unsuccessful read. Maintenance needed to restore approved recipes without readjusting the station on every shift.

System selection

Assess mark quality and lighting angles first. Then test an industrial code reader or smart camera intended for DPM. Hikrobot offers readers with configurable red and white lighting; the DPM product line describes the available versions. A PC platform becomes relevant when the same station combines multiple sides or additional OCR tasks.

Acceptance method

Use line parts that cover variation in marking, oil, position and surface condition. Define the permitted no-read rate, how an unsuccessful read is reported to the PLC and which recovery action follows. General guidance and selection criteria are covered under Traceability & OCR.