Export a PLC block to SimaticML XML with TIA Portal Openness

SimaticML is the XML format TIA Portal Openness uses to move PLC blocks in and out of a project. This guide exports one block, or every block, to XML: first with plain Openness in C#, then with PLCWare's HTTP API and MCP tools. It applies to TIA Portal V21.

Before you start

An Openness application connected to TIA Portal V21 with a project open. If you have not set that up yet, see Set up TIA Portal Openness on Windows.
The PLC must not be online.
Only consistent blocks export. If the block changed since the last compile, compile it first (Compile a PLC from code).
Supported block types: FB, FC, OB and global DB. Supported languages: STL, FBD, LAD, GRAPH and SCL.

Export one block with Openness (C#)

using System.IO;
using Siemens.Engineering;
using Siemens.Engineering.SW;
using Siemens.Engineering.SW.Blocks;

static void ExportBlock(PlcSoftware plcSoftware)
{
    PlcBlock block = plcSoftware.BlockGroup.Blocks.Find("FB_Motor");
    block.Export(new FileInfo(@"D:\Export\FB_Motor.xml"), ExportOptions.WithDefaults);
}

ExportOptions decides how much goes into the file:

Option	What the file contains
`ExportOptions.None`	Only data that was modified or differs from the default, plus what the import needs
`ExportOptions.WithDefaults`	The default values too
`ExportOptions.WithReadOnly`	The write-protected values too

Combine the last two with ExportOptions.WithDefaults | ExportOptions.WithReadOnly. The file is written in English, and project texts are exported in every language the project has.

TIA Portal V21's Openness libraries write SimaticML of engineering version V21 and can read files from V18 to V21.

Export every block, user groups included

static void ExportAll(PlcSoftware plc, string folder)
{
    Directory.CreateDirectory(folder);
    ExportBlocks(plc.BlockGroup.Blocks, folder);
    foreach (PlcBlockUserGroup group in plc.BlockGroup.Groups)
        ExportGroup(group, Path.Combine(folder, group.Name));
}

static void ExportGroup(PlcBlockUserGroup group, string folder)
{
    Directory.CreateDirectory(folder);
    ExportBlocks(group.Blocks, folder);
    foreach (PlcBlockUserGroup sub in group.Groups)
        ExportGroup(sub, Path.Combine(folder, sub.Name));
}

static void ExportBlocks(PlcBlockComposition blocks, string folder)
{
    foreach (PlcBlock block in blocks)
        block.Export(new FileInfo(Path.Combine(folder, block.Name + ".xml")), ExportOptions.WithDefaults);
}

A know-how protected block exports only its public interface unless you unlock it first with PlcBlockProtectionProvider.

Export with PLCWare

PLCWare's serve app wraps the same Openness calls behind a local HTTP/JSON API (default http://localhost:5000), and the tia MCP server exposes them as tools for an AI assistant. Exporting only reads the project, so it works on every plan, Basic included.

One block, returned inline

$r = Invoke-RestMethod "http://localhost:5000/plcs/PLC_1/blocks/FB_Motor/xml"
$r.xml | Out-File FB_Motor.xml -Encoding utf8
$r.contentHash

The answer is { name, options, contentHash, contentHashError, xml }. Add ?options=WithDefaults (or None, WithReadOnly, combined with ,) to choose the export options. The MCP tool is tia_export_block with { "plc": "PLC_1", "block": "FB_Motor" }.

Every block and type, into a folder

Invoke-RestMethod -Method Post "http://localhost:5000/plcs/PLC_1/export" `
  -ContentType "application/json" -Body '{"directory":"C:\\export"}'

The blocks go to Blocks\ and the types to Types\ under that directory, on the machine where serve runs, and the answer lists each file with its SHA-256 and size. The MCP tool is tia_export_xml; use it when a project is too big to come back in one tool result.

Prove the project still matches the XML in git

Do not compare hashes of two raw exports: two exports of the same block differ in <Created> and in the UIds. Pass the committed XML to tia_block_compare instead. It compares the block in the project with your file after normalizing both (it ignores formatting, the BOM, <Created> and UIds) and answers verdict: "equal" or "different".

Other details worth knowing:

Exporting an inconsistent block compiles it first, which can regenerate its instance DB. Export and commit the instance DB too.
contentHash is the hash the stale-write guard checks before an import overwrites a block (see Import LAD, FBD and SCL blocks). The guard needs PLCWare app 1.7.0 or later.
tia_block_render turns a SimaticML export into readable pseudo-SCL, network by network, without a running TIA Portal. It is handy for reviewing LAD and FBD blocks in a pull request.
Consistent F-blocks can be exported and imported again, but the safety system's own F-system blocks cannot be exported.

Start your free 30-day trial

PLCWare runs these steps for you, or for your AI assistant, against TIA Portal V21. The trial lasts 30 days, includes the Pro scopes, needs no card and does not renew. You need TIA Portal V21 with a STEP 7 Professional license, bought separately from Siemens.

Start the free 30-day trial · Download the app

TIA Portal, SIMATIC and Siemens are trademarks of Siemens AG. PLCWare is an independent product for TIA Portal and is not affiliated with or endorsed by Siemens.