Logging Pipe Pressure Test Data with WinCC Flexible PC Runtime

Overview: Pipe Pressure Test Data Logging Requirements

A hydrostatic or pneumatic pipe pressure test station is a sequential, data-intensive application. For every test piece the operator must capture a defined set of metadata (Customer Name, Order Number, Pipe Number, batch code, test date/time, operator ID, ambient temperature, test medium) and a high-resolution trend of the test pressure versus time. The metadata must travel with the trend so that any pressure curve retrieved months later can be unambiguously associated with the originating order and pipe. Because pipe pressure testing is a quality-critical procedure typically performed against specifications such as ASME B31.3, EN 13480, or internal QC procedures, the data must be tamper-resistant, time-stamped, and stored for several years.

Siemens WinCC Flexible 2008 PC Runtime is a viable host for this application because it provides, in one environment, tag I/O, a relational process-value archive, a trend view, an integrated report designer, and a configurable operator screen. The pieces required for the pipe-test workflow are:

• Operator-entered alphanumeric fields (Customer Name, Order Number, Pipe Number)
• Acquired pressure value from a transducer (typically 4-20 mA or 0-10 V) brought into the runtime via a tag
• A continuously sampled pressure trend (process value archive)
• Per-pipe test report combining the trend, the metadata, and pass/fail flags
• Long-term storage on disk in the runtime database (RDB)

The base WinCC Flexible PC Runtime already contains the trend, alarm, and report engines. The element that turns a live display into a logged, retrievable record is the optional Archives package, which must be licensed separately on every PC runtime.

WinCC Flexible PC Runtime Architecture

PC Runtime sits on a Windows workstation (Windows XP SP2/SP3, Windows Server 2003, or Windows 7 32-bit depending on the installed service pack). It exchanges process values with a SIMATIC S7 PLC over MPI, PROFIBUS, or PROFINET/Ethernet using the integrated S7 driver set, or with any third-party controller via OPC. The four internal subsystems used by the pipe-test workflow are:

The data flow from sensor to printed certificate is shown in the following diagram.

Licensing the WinCC Flexible Archives Option

The base WinCC Flexible PC Runtime can display trends but does not persist them across restarts or provide them to the report designer for historical retrieval. To log the pressure trend and pull it into the per-pipe certificate, you must license the archives option package.

Key licensing rules that bite first-time users:

• Each PC Runtime that writes archives requires its own 6AV6 618-7ED01-3AB0 licence. The licence is tied to the runtime, not to the engineering station.
• The licence key is installed with the Automation License Manager. A missing or invalid key causes the runtime to start in demo mode: the project loads, but a watermark is overlaid and the runtime periodically issues alarm 140002 "License not found".
• You can install the engineering project and exercise the entire archive + report chain in demo mode before purchase. Use this to validate the configuration before procuring licences.
• For older WinCC Flexible 2005, 2007, and 2008 SP1/SP2 projects the same MLFB is documented in the Siemens ST80 catalogue, pages 4/18 to 4/19.

System Requirements and Prerequisites

For a single-station pipe test bench the engineering and runtime may be installed on the same PC, but production environments usually separate them.

The runtime must be able to write to its installation directory (typically C:\Program Files\Siemens\Automation\WinCC Flexible\RT) because the RDB files (e.g. ARCHIVE\*.ldb) are created there by default.

Configuring Tags for the Pipe Test Workflow

The pressure curve and the metadata need different tag classes because the metadata is operator-entered and must be read back into the report at print time.

External tags are bound to the PLC through the configured connection (S7 Ethernet / MPI / PROFIBUS). Use the Scaling property of the tag to convert the raw transducer word (e.g. 0-27648 from a S7 AI module) to engineering units:

Pressure_Actual.scaling = linear
Pressure_Actual.low  = 0.0   // bar
Pressure_Actual.high = 200.0 // bar
Pressure_Actual.raw_low  = 0
Pressure_Actual.raw_high = 27648

The internal string tags Order_Number, Pipe_Number, Customer_Name, and Operator_ID live only in the runtime; they survive a screen change but are reset when the runtime restarts. If the metadata must persist across power cycles, store them in the S7 PLC and read them back as external tags.

Setting Up the Pressure Process Value Archive

Open Archive > Process Value Archive in the WinCC Flexible Explorer and create a new archive named Pressure_Archive. Configure the acquisition and archiving behaviour as follows.

Add a single archive tag referencing Pressure_Actual. The runtime will produce a sequence of timestamped rows in the RDB; the trend view and the report designer both consume this same sequence.

Operator Screen Design with Alphanumeric Inputs

A typical pipe-test screen contains three blocks:

1. Header block - I/O fields for Order_Number, Pipe_Number, Customer_Name, Operator_ID. Bind each to the corresponding internal tag.
2. Live block - numeric output field showing Pressure_Actual with a coloured bar, state indicator showing Test_State.
3. Trend block - a Trend View object showing Pressure_Archive in a 5-15 minute rolling window.

To bind the data to the correct test, configure the Pipe Number I/O field with the Change Value event executing a function list. A minimal function list is:

1. Set Test_Start_Time = current date/time.
2. Copy Pipe_Number into a string tag Active_Pipe_ID that the report designer references.
3. Trigger print job Print_Pipe_Certificate on the configured printer.

This guarantees that the metadata shown on the printed certificate exactly matches the trend segment archived for that pipe. If you only want to log without printing, replace step 3 with a tag write to a "Report_Ready" tag that the report viewer polls.

Generating Per-Pipe Test Reports

Open Report > Report Templates and create Pipe_Certificate.rpl. The WinCC Flexible Report Designer combines static layout objects with dynamic fields that reference tags and archive segments.

Configure a Print Job named Print_Pipe_Certificate with output target Printer or File (PDF). The print job is then invoked from the function list attached to the Pipe_Number change event, as described above.

Database Integration and Long-Term Storage

The RDB-backed process archive can be queried directly from outside WinCC Flexible in two common ways:

1. CSV export on segment close: in the archive configuration, enable "Export on segment change" with delimiter ;. This produces flat files such as PipeCert_2026_05_22.csv that any downstream QA system can ingest.
2. ODBC tag connector: with the optional WinCC Flexible/Connectivity Pack (separate MLFB, see ST80 page 4/20) you can define ODBC tags that read or write external SQL databases, allowing the pipe-test results to flow directly into a SQL Server QA database.

For typical 5-year retention required by QC, allocate at least 100 GB of disk to the archive partition and configure daily backup of closed segments.

Verification and Commissioning Checklist

Use the following checklist before signing off the station. Items 1-4 can be completed in demo mode without the archives licence; items 5-9 require the 6AV6 618-7ED01-3AB0 licence installed.

1. Compile the project without warnings. WinCC Flexible raises warning 190006 if any screen references a tag that does not exist.
2. Simulate the project: enter a dummy Order_Number and Pipe_Number and verify the trend updates.
3. Trigger a manual report print and inspect the layout.
4. Power-cycle the runtime; confirm the trend view restarts empty (expected for in-memory trends).
5. Run the runtime with the archives licence: verify a row appears in the RDB every second (System Information > Archive Status).
6. Change Pipe_Number at runtime; confirm the print job fires and the report references the new metadata.
7. Open the RDB with the WinCC Flexible Archive Viewer and confirm a contiguous pressure curve is stored for the test interval.
8. Export a CSV of the last hour and plot it in Excel; verify timestamps match the runtime clock within 1 s.
9. Run the test bench through a full ramp + hold + depressurise cycle and confirm the report contains the entire pressure profile, including the hold plateau.

Troubleshooting Matrix

Migration Path to TIA Portal / WinCC

WinCC Flexible 2008 has been in maintenance phase for several years. New projects should normally be built in TIA Portal with WinCC Comfort or WinCC Advanced for Comfort Panels, or WinCC Professional for PC Runtime. The architectural concepts covered here - tags, process value archive, trend view, report designer, print jobs - all exist in WinCC Professional with the same logical model. The archives licence equivalent in TIA Portal is included in the WinCC Professional base licence for PC Runtime, but the underlying mechanism is the SQL-based archive rather than the WinCC Flexible RDB, so existing archives must be re-engineered.

For existing pipe-test installations that already run WinCC Flexible 2008 PC Runtime, the configuration described above is sufficient for the projected lifecycle of the test bench. Order the Archives licence with the correct suffix from the current Siemens Industry Mall entry to avoid the common pitfall of an SP5 build being delivered with an SP3 licence.

FAQ