jfk-solutions.TiaFileFormat.S7CommPlus 2025.10.22.1

TiaFileFormat.S7CommPlus

Integration helpers for combining online S7CommPlusDriver metadata with TiaFileFormat models.

This library is aimed at tooling that reads Siemens S7-1200/S7-1500 PLC data over S7CommPlus and wants to reuse the same block, network, call-path, and alarm-source concepts used by TiaFileFormat.

Features

• Convert online PLC block content into TiaFileFormat CodeBlock models.
• Build a catalog of online blocks, call sites, instance DB candidates, and calling paths.
• Resolve S7CommPlusAlarm source relation IDs back to source blocks and known calling paths.
• Build TIS watch request and simple trigger blobs for online block-view experiments.
• Create, discover, activate, observe, and decode PLC-owned traces through a typed high-level API.
• Discover downloaded TIA watch-table definitions over S7CommPlus, including rows, multilingual comments, display formats and runtime addresses.
• Discover PROFINET devices on local network interfaces with DCP identify requests.

Package

The package is published as:

jfk-solutions.TiaFileFormat.S7CommPlus

NuGet: https://www.nuget.org/packages/jfk-solutions.TiaFileFormat.S7CommPlus/

Requirements

• .NET SDK 8.0 or newer
• Target frameworks: net8.0 and net9.0
• jfk-solutions.TiaFileFormat 2026.8.27.3 or newer
• DotNetProjects.S7CommPlusDriver 3.3.0 or newer
• Network capture support for ProfinetClientFinder through SharpPcap/Npcap

Build

dotnet restore .\TiaFileFormat.S7CommPlus.slnx
dotnet build .\TiaFileFormat.S7CommPlus.slnx

Building the project also creates a NuGet package because GeneratePackageOnBuild is enabled in the project file.

Usage

Discover Downloaded Watch Tables

var catalog = await new S7CommPlusWatchTableClient(client).GetWatchTablesAsync();
foreach (var table in catalog.Tables)
    Console.WriteLine($"{table.Name}: {table.Entries.Count} rows");

This reads native object 53, attribute 7579 (WebServer.VariableTables) over the existing S7CommPlus session. It does not use HTTP, a web login, TIA Portal, or a write-enabled connection. Driver 5.0.0 is sufficient. The raw-read bridge adapts the driver's public GetValue and blob-entry fields because its protocol value classes are internal.

Only tables selected under the CPU's Web server > Watch tables settings and downloaded to the CPU are available. Tables kept solely in the engineering project are not present in this attribute. Publication is needed to place the definitions on the CPU; reading them does not depend on web-server login rights. CanWrite describes the downloaded table's configuration and does not grant permission to write signals. Definitions and CPU state are never changed by discovery.

The decoder handles formats 1–3, preserves blank/comment rows, and rejects unknown versions, truncated records and invalid references. Native runtime addresses contain little-endian RID/local-ID/CRC words inside the big-endian record format. Format 3 preserves comments by LCID. S7CommPlusWatchTableDecoder.Decode also accepts a saved sparse-blob snapshot without a live connection.

Set S7COMMPLUS_WATCH_TABLE_TEST_ADDRESS to an authorized PLC to run the opt-in WatchTableApiTests device test. Ordinary tests use synthetic protocol data.

Create and Activate a Trace

Wrap a connected S7CommPlusClient in S7CommPlusTraceClient. The wrapper resolves symbols, compiles the definition, installs the trace, and activates it before CreateTraceAsync returns.

using S7CommPlusDriver;
using TiaFileFormat.S7CommPlus;

var traces = new S7CommPlusTraceClient(client);
var definition = new S7CommPlusTraceDefinition("Valve transition")
{
    RecordingDuration = S7CommPlusTraceDuration.FromSamples(10_000),
    Trigger = S7CommPlusTraceTrigger.RisingEdge(
        "ValveOpen",
        S7CommPlusTracePretrigger.FromSamples(2_000)),
    Storage = S7CommPlusTraceStorage.MemoryCard(
        measurementLimit: 5,
        S7CommPlusTraceStorageFullBehavior.OverwriteOldest),
    ContinueAfterDisconnect = true
};
definition.Signals.Add(S7CommPlusTraceSignal.FromSymbol("ProcessByte"));
definition.Signals.Add(S7CommPlusTraceSignal.FromSymbol("ValveOpen"));

await using var trace = await traces.CreateTraceAsync(definition);
var measurement = await traces.WaitForTraceMeasurementAsync(trace);
var values = measurement.GetSeries("ProcessByte").GetValues<byte>();

ContinueAfterDisconnect defaults to true. The installed job therefore keeps waiting, recording, or saving when the creating connection closes. Disposing S7CommPlusTrace only detaches its temporary notification subscription.

Discover Existing Traces and Measurements

Discovery includes traces installed by other clients. Configuration metadata is decoded when its format is supported; the raw protocol blobs remain available for unknown versions.

var installed = await traces.GetInstalledTracesAsync();
var selected = installed.Single(item => item.Reference.Name == "Valve transition");

// Attach without reinstalling or activating the trace.
await using var attached = await traces.OpenTraceAsync(selected.Reference);

// Explicit lifecycle operations work with rediscovered references.
await traces.DeactivateTraceAsync(selected.Reference);
await traces.ActivateTraceAsync(selected.Reference); // re-arm

// Current results and memory-card measurements have content-stable references.
var available = await traces.GetTraceMeasurementsAsync(selected.Reference);
if (available.Count != 0)
    var exactResult = await traces.ReadTraceMeasurementAsync(available[0].Reference);

var retained = await traces.GetStoredTraceMeasurementsAsync();
if (retained.Count != 0)
{
    var stored = await traces.ReadStoredTraceMeasurementAsync(retained[0].Reference);
    await traces.DeleteStoredTraceMeasurementAsync(retained[0].Reference);
}

await traces.DeleteTraceAsync(selected.Reference);

Creation, activation, deactivation, trace deletion, and stored-measurement deletion require the underlying client to have WriteEnabled = true. Discovery, result reading, and attachment are read-only. See Documentation/s7commplus/traces.md for all trigger modes, pretrigger behavior, storage, reconnect semantics, and the low-level/high-level package boundary.

Build an Online Block Call-Path Catalog

OnlineBlockCallPathCatalogBuilder reads the online block list and selected block metadata. The resulting catalog can be cached and reused by UIs or alarm workflows. Online metadata extraction remains in this package, while call-graph construction uses the protocol-neutral builder from TiaFileFormat that also supports offline projects.

using TiaFileFormat.S7CommPlus;

var catalog = await OnlineBlockCallPathCatalogBuilder.BuildAsync(client);

foreach (var path in catalog.CallingPaths)
{
    Console.WriteLine(path.DisplayName);
}

foreach (var warning in catalog.Warnings)
{
    Console.WriteLine(warning);
}

If another workflow has already loaded block metadata, reuse it instead of reading it again from the PLC:

var catalog = OnlineBlockCallPathCatalogBuilder.BuildFromLoadedBlocks(
    blocks,
    loadedBlockContents);

Resolve Alarm Sources

S7CommPlusDriver exposes alarm source identifiers decoded from CpuAlarmId. This package resolves those identifiers against an existing catalog so a UI can jump from an alarm to the related block and calling paths.

using TiaFileFormat.S7CommPlus;

var catalog = await OnlineBlockCallPathCatalogBuilder.BuildAsync(client);
var alarms = await client.GetActiveAlarmsAsync(languageId: 1031, textLists);

var selectedAlarm = alarms[0];
var source = catalog.ResolveAlarmSource(selectedAlarm);

if (source.SourceBlock != null)
{
    Console.WriteLine(
        $"{source.SourceBlock.Name} ({source.SourceBlock.Type}{source.SourceBlock.Number})");
}

foreach (var path in source.CallingPaths)
{
    Console.WriteLine(path.DisplayName);
}

ResolveAlarmSource does not read from the PLC. It only uses the supplied catalog.

Convert Online Block Content

OnlineBlockConverter turns an online S7CommPlusClientBlockContent object into a TiaFileFormat.Wrappers.CodeBlocks.CodeBlock.

using TiaFileFormat.S7CommPlus;

var content = await client.GetBlockContentAsync(block.RelationId);
var codeBlock = OnlineBlockConverter.GetOnlineCodeBlock(content);

foreach (var network in codeBlock.Networks)
{
    Console.WriteLine($"{network.SourceRefId}: {network.Title}");
}

Create TIS Watch Requests

OnlineBlockViewTisWatchRequestBuilder contains low-level helpers for building request and trigger blobs used by S7CommPlus TIS watch jobs.

using S7CommPlusDriver;
using TiaFileFormat.S7CommPlus;

var request = OnlineBlockViewTisWatchRequestBuilder.CreateForBlock(
    S7CommPlusBlockType.FB,
    blockNumber: 3001,
    watchPoints);

This API is intentionally close to the protocol. See Documentation/s7commplus/online-block-view.md for the reverse-engineering notes, live PLC findings, and current limitations.

Repository Layout

.
|-- Documentation/
|   `-- s7commplus/        Research notes and protocol references
|-- TiaFileFormat.S7CommPlus/
|   |-- *.cs               Library source
|   |-- README.md          Package-focused README content
|   `-- *.csproj
`-- TiaFileFormat.S7CommPlus.slnx

Notes on Online Block View Support

The TIS online block-view code is based on packet captures, Siemens metadata, and live PLC experiments. Simple block triggers and request/result layout are implemented, but exact S7-1500 Plus call-path disambiguation for ambiguous FB instances still depends on MC7Plus trigger-expression generation.

For implementation details and open questions, start with:

• Documentation/s7commplus/online-block-view.md
• Documentation/s7commplus/*.pdf

License

MIT. Visit http://jfk-solutions.de for more information.