Power returns and the control screen shows a position. Is the interrupted inspection ready to continue? For an Automatic Video Measuring Machine, we treat recovery as a check of the inspection state, not just a return of electrical power. Position information, programme progress, part identity and report completeness are separate facts. A restart procedure should establish all four before the next automatic result is accepted.

The accompanying VH-series video demonstrates dimensional measurement, not a power-interruption recovery test or a claim about its encoder architecture. The cover illustrates a measurement application; its efficiency wording depends on the task and comparison conditions. The recovery principles below must be implemented through the installed equipment instructions and authorised site procedures.

Separate position availability from permission to resume

An incremental position system measures movement relative to an established reference; restoring a valid position may require the prescribed referencing procedure. An absolute encoder can provide coded position information after power-up within its design, but that does not establish every machine or inspection state. The controller still has to interpret the information correctly. We do not infer a particular recovery capability from the presence of an absolute encoder alone.

A Vision Measuring System may involve work offsets, coordinate relationships, active programmes and application settings in addition to axis feedback. Retained position does not prove that the correct workpiece is present or that a pending result belongs to it. The equipment supplier and responsible integrator should define the valid restart states. Operators should follow that definition rather than bypassing a reference requirement because a numerical coordinate is visible.

Identify what was interrupted

Before restarting the measurement programme, determine whether the interruption occurred before acquisition, between features, during a required operator action, or while a report was being written. Those are different recovery cases. A partly populated report can look credible when its missing fields are not obvious. The procedure should explain how incomplete work is marked and prevented from entering the accepted-result stream.

For a Video Measuring Machine, we recommend identifying the active job, programme revision and physical part before deciding what can be retained. A timestamp alone may be insufficient when several items were being processed. Preserve available records through approved tools, and record the interruption separately from any subsequent complete measurement. Do not overwrite an earlier result simply to make the report appear uninterrupted.

Choose the permitted restart point

Some installed systems may support a documented continuation function; others may require the interrupted part to be measured again from the beginning. We would confirm the supported route and the assumptions behind it. A continuation is meaningful only when the saved feature results, coordinate state and physical setup remain applicable. If those facts cannot be established, guessing the next feature creates uncertainty about the entire record.

The same question arises with a Desktop Instant Vision Measuring Machine. A short acquisition time does not eliminate job identity or file-writing risks. If parts were removed, added or rearranged during the interruption, the relationship between physical items and retained results needs to be established again. This is a recovery decision, not a reason to assume that every instrument has identical restart behaviour.

Re-establish the approved measurement configuration

Check the configuration items required by the equipment procedure: the selected job and programme version, relevant optical settings, workpiece support and any necessary coordinate establishment. Follow the specified startup and referencing sequence. A position-recovery check cannot substitute for required safeguards, and an automatic movement should not be initiated while the setup is unresolved. The responsible person should define the release criteria in advance.

For a Vertical and Horizontal Integrated Instant Vision Measuring Machine, a programme may depend on more than one view or a prescribed part-handling sequence. The recovery record should identify which views and actions are complete, rather than merely showing that the main screen reopened. Where a part must be re-presented, the approved inspection should establish the required relationship again before results are combined.

Test recovery as a controlled acceptance case

If restart behaviour matters to production, include it in an agreed equipment trial. The supplier should approve how the interruption is simulated and which machine states can be tested without damage or uncontrolled motion. Do not perform arbitrary power cuts on operating equipment. A controlled test should demonstrate the outcome that matters: a complete, correctly identified inspection record after the documented recovery procedure.

Useful acceptance questions include whether the software clearly identifies unfinished work, prevents duplicate reporting and preserves the connection between part and result. Check what happens if an operator chooses to abandon the interrupted job. Confirm how the new complete measurement is distinguished from the interrupted attempt. These are application and data-handling questions as much as motion-control questions.

At DONGGUAN CITY HANDING OPTICAL INSTRUMENT CO., LTD., we discuss the whole inspection workflow when selecting an Optical Measuring Machine. Send your part-handling sequence, reporting requirements and recovery expectations to handing3d@163.com. We can review appropriate configurations and identify which restart functions require confirmation for the proposed controller and software. A clear recovery plan turns an unexpected interruption into a documented decision instead of an assumption.