Exporting and Auditing Inverted Binary Interconnections in SIMATIC PCS 7

In SIMATIC PCS 7, standard Chart Reference Data (Plan-Referenzdaten) exports cross-references and operand tables but omits binary interconnection negation (inversion) symbols, risking code misinterpretation during safety audits. To export all binary interconnections along with their active negation flags without declaring every block pin as a parameter, use the Process Object View (POV). In Process Object View, navigate to the 'Signals' tab or select 'Options > Process Objects > Export All I/Os...'. Inverted interconnections are explicitly designated by a leading minus sign ('-') in the interconnection column.

Binary Negation Representation in Continuous Function Chart (CFC)

In SIMATIC PCS 7 Continuous Function Chart (CFC), Boolean block input pins can be inverted directly at the interconnection point. An inverted input displays a solid black negation circle on the block terminal pin, flipping incoming true (1) signals to false (0) and vice versa prior to block algorithm execution.

While this graphical negation minimizes chart clutter by eliminating discrete inverter blocks (such as INV_B / Not01), it poses significant auditing challenges during safety assessments, functional reviews, and validation testing if documentation tools fail to capture the negation flag.

Limitations of Chart Reference Data for Auditing Negations

Engineers frequently generate documentation using Chart Reference Data (CFC > Options > Chart Reference Data or Plan-Referenzdaten). While Chart Reference Data produces comprehensive cross-reference lists for block types, global memory operands, and cross-chart interconnections, its text and CSV export formats format interconnections strictly as ChartName\BlockName.PinName -> TargetChart\TargetBlock.TargetPin.

The reference data engine completely strips the negation flag during text serialization. Relying solely on Chart Reference Data for logic auditing can lead reviewers to conclude a permissive or interlock signal is active-high when it is actually inverted into an active-low trip condition.

Exporting Negated Signals via Process Object View (POV)

The Process Object View (View > Process Object View in SIMATIC Manager) provides full programmatic exposure of block terminal attributes, including negation status:

Parameter Tab vs Signals Tab:
- In the Parameters tab, inverted inputs display with a leading minus sign (-) in the Interconnection column (e.g. -Unit1_Valves/V101.SafePos). However, only block pins configured with the attribute S7_m_c = true or declared as parameters appear by default.
- In the Signals tab, all I/O interconnections appear regardless of parameter visibility settings.
Exporting All I/O Interconnections:
- Select the target Plant Hierarchy folder in SIMATIC Manager.
- From the main menu, navigate to Options > Process Objects > Export All I/Os... (or Extras > Prozessobjekte > Alle Anschlüsse exportieren).
- Save the exported dataset as a tab-delimited text or CSV file.
- In the exported spreadsheet, inverted connections appear with the explicit - prefix in the source address field.

Managing Large Data Sets Across Plant Hierarchy Folders

In large SIMATIC PCS 7 facilities (e.g., projects exceeding 50,000 I/O points), exporting all connections across the entire multiproject will generate hundreds of thousands of rows, potentially exceeding Microsoft Excel's limit of 1,048,576 rows or exhausting system memory.

To optimize data handling:

Export by Hierarchy Subfolder: Select individual Unit folders (Teilanlagen) or Equipment Phases in the Plant Hierarchy rather than selecting the top-level project root.
Apply POV Filters: In Process Object View, configure a column filter on the Data Type column to restrict visible entries strictly to BOOL, eliminating all analog (REAL, WORD, DWORD) records from the export.
Auditing Scripting: Process exported CSV text files using Python or PowerShell scripts to instantly parse and flag all lines containing - in the interconnection column.

Comparison of PCS 7 Signal Export Interfaces

The table below contrasts tools used to extract and verify signal interconnections in SIMATIC PCS 7:

Audit ToolNegation Indicator ExportedRequires Parameter DeclarationScope of ExportPrimary Engineering PurposeChart Reference DataNo (Strips negation prefix)No (All charts)Entire AS stationCross-reference validation & address tracingPOV - Parameters TabYes (- prefix shown)Yes (Only declared parameters)Selected Hierarchy folderTuning faceplate parameters & limitsPOV - Signals TabYes (- prefix shown)No (All mapped signals)Selected Hierarchy folderSignal tracing and hardware cross-referencingPOV - Export All I/OsYes (- prefix shown)No (Every block pin exported)Selected Hierarchy folderComprehensive design reviews & logic auditingImport/Export Assistant (IEA)Yes (Captured in IEA templates)Yes (PTT-defined I/Os)Tag Type instancesBulk replication of process tag types

Verification

Validate that exported data correctly captures binary negations:

In a CFC chart, intentionally invert a Boolean input on a known block (e.g. pin Permit on MotL).
Open SIMATIC Manager, navigate to that chart's Plant Hierarchy folder, and open Process Object View.
Switch to the Signals tab and locate the specific block pin.
Confirm that the Interconnection field begins with a leading minus sign (-).
Execute Options > Process Objects > Export All I/Os..., open the resulting CSV in a text editor, and confirm the text string -<SourceChart\SourceBlock.SourcePin> is present.

Limitations and Operational Precautions

Adhere to the following engineering precautions when managing negated connections:

Never Modify Negation Manually in CSV: If importing edited CSV files back into Process Object View, ensure the minus sign is not accidentally stripped or added by spreadsheet auto-formatting (e.g. Excel treating - as a formula).
Documentation Standards: Many pharmaceutical and nuclear validation standards (GAMP 5) forbid the use of pin-level negations; engineering guidelines often mandate using explicit Not logic blocks for auditable clarity.
Export Filtering: Ensure all charts in the selected hierarchy are compiled before exporting to guarantee interconnection pointers reflect the latest compiled AS state.

Engineer FAQ

Why doesn't Chart Reference Data export the '-' sign for inverted connections?

The Chart Reference Data export engine was designed primarily for compiler address tracing and cross-referencing rather than functional logic auditing. It formats connections strictly by block and parameter identifier without symbol modifiers.

Can I export negations using the Import/Export Assistant (IEA)?

Yes, Process Tag Types (PTT) and Process Tag Types with IEA parameters capture negation status in the parameter column. However, it only includes block pins that were explicitly declared in the PTT template.

How can I prevent Excel from converting the leading '-' sign into a formula error during import?

When opening the exported CSV or tab-delimited text file in Excel, use the Text Import Wizard and format the interconnection column explicitly as 'Text' rather than 'General'.