Difference between physical meters and accounting in NDD Print

What are physical counters?

Physical counters refer to the internal counters in a printer or multifunction device.

These counters are triggered by sensors in the equipment itself that detect the passage of paper during the printing process. Since the reading takes place directly within the printer, the physical counters represent the pages that the equipment has recognized as having been produced.

What is accounting?

NDD Print accounting records print, copy, and scan events captured by the software.

These events can be obtained through different modules of the solution:

• NDD Print Agent, which captures information from the Windows spooler;

• NDD Print MF, which uses logs generated by the multifunction device;

• NDD Print Embedded (Embedded Collector), which uses information provided by the printer itself.

Since NDD works with equipment from different manufacturers, models, and technologies, the accounting method may vary depending on each environment.

In general:

• when data is captured from the multifunction device’s logs or via embedded modules, the accounting figures tend to be closer to the physical meters;

• when data is captured via the Windows spooler, larger discrepancies may be observed, as the entry may occur before the print job is physically completed.

Why might the values differ?

Physical counters and accounting do not measure exactly the same information.

While physical counters represent the printer’s internal meters, accounting represents events captured and interpreted by the software.

For this reason, differences between these two sets of information are to be expected.

These differences may occur because:

• capture occurs at different points in the process;

• each method uses its own criteria to interpret events;

• data may be recorded at different times;

• manufacturers implement different behaviors across their equipment.

Therefore, a discrepancy should not automatically be processed as a failure.

Situations that can generate discrepancies

Incorrect date and hour

When the server or multifunction device has an incorrect date and hour, the same event may be recorded in different periods.

This behavior is typically noticed mainly during monthly closings.

Paper jam followed by cancellation

When a paper jam occurs and the user cancels the print job, there may be a discrepancy between:

• the document sent;

• the document logged;

• the document actually produced.

Depending on the capture method, the accounting system may record the entire job, part of it, or some other value, while the physical meter tends to record only the pages recognized by the printer.

Print cancellation by the spooler

When a print job is canceled by the Windows spooler, the software may have already recorded the event before the print job was physically completed.

This behavior occurs primarily when accounting is based on the spooler.

Prints outside the monitored workflow

Prints performed outside the monitored workflow may increment only the physical counters.

This can occur, for example, in:

• direct IP printing;

• printing without using the monitored server;

• printing using the printer’s native features;

• printing performed by unmonitored applications or protocols.

Printing via USB or SD Card

Prints executed directly on the multifunction device using USB devices, SD cards, or other local resources may increase the physical meters without generating accounting entries.

This behavior depends on the equipment’s manufacturer, model, firmware, and embedded platform.

Pages Generated by the Printer Itself

The printer may generate internal pages, such as:

• configuration page;

• test page;

• network report;

• supplies report;

• maintenance pages;

• error pages;

• reports issued by the equipment’s panel.

These pages typically increment the physical counters but are not always recorded by the accounting system.

Information provided by the driver

In print jobs processed by the spooler, the driver may report a different quantity of pages than the number of pages actually produced.

This discrepancy may be related to document rendering, the number of copies, duplex printing, paper size, or other driver characteristics.

In such cases, the accounting system may record a higher volume than that recognized by the printer.

Duplex prints with an odd number of pages

In duplex documents with an odd quantity of pages, some equipment interprets pages, sides, and sheets differently.

Depending on the manufacturer’s implementation, the duplex cycle may generate an additional increase in the meters.

This behavior should always be verified for the specific manufacturer and model being analyzed.

How to properly analyze a discrepancy

Before concluding that a failure exists, consider:

• what data capture method was used;

• where the data was obtained;

• which period is being compared;

• which report is being used in the analysis.

It is also important to remember that the NDD Print 360 report and the MPS meter report serve different purposes.

To compare accounting data and physical meters, you should preferably use the MPS comparative report, as it was developed specifically for this type of analysis.

Conclusion

Differences between physical meters and accounting data are to be expected, as each set of information is obtained through distinct mechanisms and at different stages of the printing process.

Rather than searching for exactly matching values, the analysis should verify whether the discrepancy falls within the expected range for the data collection method used or whether there are indications of configuration, operational, or infrastructure failures that warrant further investigation.

Last updated: July 29, 2026