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DCC Export

calServer generates Digital Calibration Certificates (DCC) according to the specification of the Physikalisch-Technische Bundesanstalt (PTB), version 3.3.0. This section describes the technical implementation, the generation process, and the setup.

Basics

The DCC is a machine-readable XML format for calibration certificates, standardized by the PTB. It enables automated exchange of calibration data between laboratories and their customers. calServer implements:

  • XML generation according to PTB DCC v3.3.0
  • Embedding of the PDF calibration certificate as Base64 in the XML
  • XSD validation of the generated XML
  • Mapping of calServer database fields to DCC XML elements via a configurable JSON file

Architecture

The DCC generation comprises three components:

FrontendCalibration
        │
        ▼
DccXmlGenerator          ◄── dcc-mapping.json
        │
        ├── generate()          Build XML structure
        ├── embedPdf()          Embed PDF as Base64
        └── validate()          Validate against XSD
        │
        ▼
    DCC XML file

DccXmlGenerator

The class DccXmlGenerator (under httpdocs/protected/components/) is the central entry point. It:

  • Reads the mapping configuration from dcc-mapping.json
  • Loads the calibration record with relations (inventory, customer, results, standards)
  • Creates a DOMDocument with the DCC namespaces
  • Builds the administrativeData and measurementResults sections
  • Optionally embeds the rendered PDF as Base64
  • Validates the result against the PTB XSD schema

The key namespaces:

Namespace URI
DCC https://ptb.de/dcc
SI https://ptb.de/si

DCC Mapping

The mapping between calServer fields and DCC XML elements is defined in a JSON file (dcc-mapping.json) that is delivered together with the report templates. This file describes which database fields are transferred to which XML elements.

The mapping is managed via the admin model AdminReportSetting:

  • hasDccMapping() -- Checks whether a DCC mapping exists for a report template
  • getDccMappingPath() -- Returns the path to the mapping file

ReportEngineManager

The class ReportEngineManager controls whether DCC generation is active:

// Check if DCC is globally enabled
Yii::app()->reportEngine->isDccPluginEnabled();

The feature flag enable_dcc_plugin is set system-wide in the application properties.

XML Structure

A generated DCC follows this structure:

<?xml version="1.0" encoding="UTF-8"?>
<dcc:digitalCalibrationCertificate
    xmlns:dcc="https://ptb.de/dcc"
    xmlns:si="https://ptb.de/si"
    schemaVersion="3.3.0">

    <dcc:administrativeData>
        <!-- Laboratory information, customer information,
             calibration object, calibration date -->
    </dcc:administrativeData>

    <dcc:measurementResults>
        <!-- Measurement results with SI units -->
    </dcc:measurementResults>

    <dcc:document>
        <!-- Embedded PDF (Base64) -->
    </dcc:document>
</dcc:digitalCalibrationCertificate>

Generation Process

The complete workflow of a DCC generation:

  1. The user triggers report generation for a calibration
  2. The ReportEngineManager checks whether the DCC plugin is enabled
  3. The report template is checked for an existing DCC mapping
  4. The DccXmlGenerator is instantiated with the path to the mapping file
  5. generate($ctag) loads the calibration data and generates the XML
  6. embedPdf($pdfPath) embeds the rendered PDF report
  7. validate() validates the XML against the XSD schema
  8. The finished XML is saved and made available for download

Setup

Prerequisites

  • calServer version with DCC support
  • JasperReports template with associated dcc-mapping.json
  • PTB XSD schema (optional, for validation)

Enable Feature Flag

The DCC plugin is enabled via the application properties:

Section: features > report_engine > enable_dcc_plugin = 1

Set Up Report Template

  1. Upload the JasperReports template to the directory httpdocs/reports/calibrations/
  2. Place the associated dcc-mapping.json in the same directory
  3. Configure the report template under Administration > Report Management

Create Mapping File

The dcc-mapping.json defines the mapping of calServer fields to DCC XML elements. The file is created per report template and references the internal field names (C-series for calibration fields, I-series for inventory fields).

Languages

The DCC export supports German and English. The language selection is passed as a parameter when calling generate():

$generator = new DccXmlGenerator($mappingPath, $xsdPath);
$dom = $generator->generate($ctag, 'de'); // or 'en'

Troubleshooting

Problem Cause Solution
Failed to parse dcc-mapping.json JSON file is malformed or missing Check path and JSON syntax
Calibration not found Invalid calibration ID Check CTAG value
PDF file not found for DCC embedding PDF was not generated Check report generation, review Report Runner logs
XSD validation error XML does not conform to the schema Check mapping file and calibration data

Further Information