STEP7 to EPLAN: Hardware Configuration Macro Import Workflow

Overview

Engineers commissioning SIMATIC S7-300, S7-400, ET 200, or older S7-200 systems frequently need to mirror the STEP 7 hardware configuration into an EPLAN Electric P8 electrical schematic. The instinctive path — exporting the *.cfg* file out of SIMATIC Manager > HW Config and dragging it into EPLAN — fails because EPLAN has no parser for the STEP 7 binary configuration format. The two systems do not speak a common interchange format natively.

The supported workflow is to obtain Siemens-prepared EPLAN macros from either the Siemens CAx download area or the EPLAN Data Portal, then place those macros on the appropriate schematic pages and assign them to the same Siemens part numbers used in HW Config. This article documents the exact procedure, the supported file formats, the parts-database mapping, and a troubleshooting matrix for the common failure modes.

The CFG Limitation: Why STEP 7 HW Config Output Is Not EPLAN-Compatible

When you save a station in SIMATIC Manager > HW Config > Station > Save (or Save and Compile), the following artefacts are generated:

The *.cfg file is a packed binary record specific to STEP 7. EPLAN Electric P8 (versions 2.1, 2.7, 2.9, 2022, 2023, 2024, and the current 2025 release) does not contain an importer for that format. The same restriction applies to TIA Portal's *.ap* project archive — TIA can export device labels as CSV but cannot push a working schematic macro set into EPLAN. As of writing there is no Siemens-supplied bidirectional STEP 7 < > EPLAN bridge.

Supported EPLAN Import Formats for Siemens Components

The *.ema file is the canonical deliverable. A single archive can carry a schematic symbol, a terminal-strip representation, a 3D mounting model, and the full parts record (article number, manufacturer, technical properties). This is why Siemens ships one archive per module rather than separate schematic and parts files.

Prerequisites

1. EPLAN Electric P8 2.7 or newer. Versions 2.1 (the one referenced in earlier forum questions) do not support EPLAN Data Portal direct download — they require manual *.ema import. Versions 2022 / 2023 / 2024 / 2025 have the Data Portal integrated as a ribbon tab (Home > Parts > Data Portal).
2. Valid EPLAN Data Portal account. A free registered account is sufficient for searching; bulk download and watchlists require an EPLAN subscription or a maintenance contract.
3. Siemens Support account for CAx download. support.industry.siemens.com registration is free; some macro archives require a Siemens Industry Online Support registration.
4. SIMATIC Manager (STEP 7 V5.5 or V5.6) or TIA Portal V15 / V16 / V17 / V18 installed locally so you can read the existing *.cfg file and confirm the exact module order, MLFB (article number), and rack/slot positions you need to mirror in EPLAN.
5. List of Siemens part numbers actually present in the station — pulled from HW Config: Station > Print > Module List, or from the offline catalog via View > Catalog.

STEP 7 Hardware Configuration: What to Extract Before Touching EPLAN

Before you start placing macros in EPLAN, capture the canonical data from STEP 7 so the schematic exactly mirrors the rack:

1. Open the station in HW Config.
2. From the menu, select Station > Print > Module List. This produces a text or printable list showing each slot's MLFB (e.g. 6ES7 313-6CF40-0AB0), firmware version, and I/O address ranges.
3. From Station > Export, choose Configuration file (*.cfg). Save it locally for reference; you will not import it into EPLAN but you will keep it for audit traceability.
4. Open View > Catalog and write down every MLFB you intend to draw, including:
   • Power supply (PS)
   • CPU
   • Signal modules (SM) — DI / DO / AI / AO
   • Function modules (FM)
   • Communication processors (CP)
   • Interface modules (IM) for ET 200
5. Capture the terminal assignment: HW Config > select module > right-click > Properties > Addresses records the I/Q address. The schematic terminal letters (e.g. 1, 2, 3, 4, 5, 6, 7, 8 for an SM 321) come from the module datasheet, not from HW Config.

Method 1 — Siemens CAx Download (formerly CAXorder)

Siemens publishes EPLAN-compatible CAx data through their Industry Online Support portal. The legacy "CAXorder" link has been folded into the CAx download area.

1. Open Siemens Industry Online Support and search for the MLFB (for example, type 6ES7313-6CF40-0AB0 into the product search).
2. From the product page, navigate to Support > CAx data (or follow the CAx download help entry).
3. Select EPLAN Electric P8 as the target format and download the *.zip archive.
4. Extract the archive. Typical contents:
   • *.ema — schematic / terminal / 3D macro
   • *.dxf or *.dwg — 2D geometry
   • *.step — 3D model
   • *.pdf — datasheet and terminal plan
5. Repeat for every MLFB in your station list. Place all extracted *.ema files in a single staging directory such as C:\EPLAN_Macros\S7300_Station01\.

Method 2 — EPLAN Data Portal

The Data Portal is the modern workflow and is integrated into EPLAN from version 2.7 onward.

1. Inside EPLAN, open the parts database view: Menu > Master Data > Parts.
2. Click Search in Data Portal (or ribbon: Home > Parts > Data Portal).
3. Filter by manufacturer: Siemens AG. Optionally narrow by part-number prefix (e.g. 6ES7 313 for S7-300 CPUs).
4. Locate the matching part number, right-click and select Download to parts database. This action:
   • Adds the part to your EPLAN parts database with full commercial and technical properties
   • Downloads the matching macro to %USERPROFILE%\Documents\EPLAN\Data\Macros\
   • Associates the part number with the macro for future placements
5. Confirm the download by clicking Refresh in the parts manager; the new Siemens part should appear with a green EPLAN Data Portal icon.

The Data Portal search returns both current EPLAN 2024+ macros and older *.zw1 macros for projects opened in EPLAN 2.1 or earlier. Always choose the version that matches your EPLAN release unless you have a documented reason to downgrade.

Method 3 — Manual Macro Construction (Fallback)

If Siemens has not yet released a macro for a particular module — common with very recent firmware revisions or new IM 153 / ET 200SP variants — build the macro inside EPLAN:

1. Draw the schematic symbol on a new macro page: Insert > Symbol. Use the IEC symbol library, search by function (e.g. "16-channel digital input module").
2. Add terminal designations: Insert > Terminal / Terminal Strip. Define each terminal number, its function, and the wire cross-section reference.
3. Create the macro: File > Export as Macro > Window Macro (*.emw). Save it in %USERPROFILE%\Documents\EPLAN\Data\Macros\.
4. Create the matching parts record: Master Data > Parts > New. Fill in the MLFB exactly as STEP 7 records it, set manufacturer to Siemens AG, and link the macro you just saved under the Macro tab.

STEP-by-Step: Importing Siemens Macros into EPLAN Electric P8

1. Confirm macros are downloaded (Method 1 or Method 2 above).
2. Open the target EPLAN project. If the project does not yet exist, create one with the matching station name: Project > New > Project name = Station_01.
3. Set the project template / basic project to one that uses IEC symbols (typical in EU installations). North-American installations may use the NFPA / JIC templates; the macro set is the same but the sheet frame differs.
4. Open the page where the module should appear. For S7-300 stations use the page structure: => Cabinet / Rack / Slot.
5. Place the macro: Insert > Macro > Insert Window Macro (or Place from Data Portal). Navigate to the staged *.ema or the Data Portal browser.
6. Anchor the macro at the desired coordinate. The macro brings all its graphical and logical content: terminal designations, DT/PE markings, internal wiring identifiers.
7. Assign the part: right-click the placed symbol > Properties > Parts tab > select the matching Siemens article number. This binds the symbol to the parts database and enables the bill-of-materials to roll up correctly.
8. Repeat for every slot in the STEP 7 rack until the schematic reflects the same module order. Maintain slot order left-to-right in the schematic to match the physical rack order for easier troubleshooting in the field.
9. Save the project. EPLAN saves macros by reference inside the project file. Deleting the source *.ema from disk after import will break existing placements — keep the source directory in your revision-control system.

Linking the EPLAN Schematic Back to STEP 7 Symbols

The schematic side is solved by the macros; the symbol side (the I/Q tag names inside the STEP 7 project) still has to be re-typed or imported manually:

1. In STEP 7, export the symbol table: Options > Symbol Table > Export. Choose *.asc with semicolon separators, or *.dif if you need formatting compatibility.
2. In EPLAN, open Utilities > Connections > Connection Designation for the macro you placed. Paste the symbolic tag (e.g. I 0.0 / Motor_Run) into the connection designation.
3. For bulk import, EPLAN 2022+ supports the *.csv connection list import under Project > Import > Connections. The CSV column order is:
   • Page / Higher-level function / Page name
   • Connection designation source
   • Connection designation target
   • Signal name
   • Wire cross-section
   • Color / Function definition
4. Use the EPLAN plug-in Signal Flow / Connection Numbering (Project Data > Connections) to update all connection designations in one pass after CSV import.

Specifications and Compatibility Matrix

The macro naming is set by Siemens and may include the firmware index (e.g. -1BL00- vs -1BL01-). Always check the macro's parts-record linkage before mass placement — a firmware mismatch will produce a wrong MLFB in the EPLAN parts list even though the graphic looks correct.

Verifying the Import

1. Cross-check parts list: Project > Reports > Parts List. Compare the EPLAN parts list to the HW Config module list exported in Step 2. Every slot should have a matching MLFB.
2. Cross-check terminal designations: for an SM 321 DI 16 × 24 V DC the macro should show terminals 1–8 (channel 0), 9–16 (channel 1), with terminal 20 as M / ground reference. Manually trace the macro's terminals against the Siemens datasheet shipped in the CAx archive.
3. Cross-check 3D model: Project > 3D Mounting Layout > Open Layout Space. The 3D macros from Siemens should snap onto the rail in correct order. If a 3D macro does not snap, the macro file is the wrong firmware revision.
4. Run a connection-numbering pass: Project Data > Connections > Number / Rename. This validates that every macro placed in the schematic has reachable, non-duplicate connection designations.
5. Open the EPLAN project on a second station (or in the same release) and confirm macro bindings resolve. EPLAN 2.1 cannot open projects saved in 2024 unless upgraded; macro references stored in pre-2.1 format (*.zw1) are not portable to 2024+ projects.

Troubleshooting Matrix

Alternative Approaches for Special Cases

For TIA Portal V18+ stations: TIA can export a CSV device list under Project tree > Devices & Networks > Export. Combine the CSV with EPLAN's CSV connection import to reduce manual typing for large S7-1500 / ET 200SP stations. Macro sourcing remains identical through the Data Portal.

For PROFINET topologies: The PROFINET device name and IP address are not part of the EPLAN macro. They live in the EPLAN connection-designation layer or in a separate Network topology page, where the MAC address and device name are entered as device-tag properties.

For cabinet design integrations: When the schematic is being laid out in EPLAN Pro Panel or EPLAN Cabinet Engineering, the Siemens-supplied 3D STEP file from CAx can be imported as a placement object. The macro's 3D Mounting tab must reference the same STEP file; otherwise the placement drifts from the schematic by millimeters, causing bolt-pattern mismatches at cabinet build time.

For revision tracking: Add the Siemens CAx macro file checksum (SHA-256) to the EPLAN project documentation under Project > Reports > Project Properties. This lets auditors confirm the schematic is bound to a vendor-supplied macro rather than a manually edited variant.

FAQ