Free Siemens to Ignition tag converter (TIA Portal, STEP 7)

Updated: 24 October 2026 · SIM Solutions

Short answer

Export the tag table from TIA Portal (or the symbol table from STEP 7), drop the file into the converter below and download tags.json. Then import it in the Ignition Designer: Tag Browser, Import Tags. The converter turns Siemens addresses such as %DB10.DBD4 or %MW10 into Ignition OPC item paths such as [PLC1]DB10,REAL4 or [PLC1]MW10 and maps the data types. It runs in your browser, so nothing is uploaded.

Why a converter

Ignition's Siemens driver cannot browse a PLC. Inductive Automation's documentation says the S7 protocol does not support tag browsing, so every tag needs its address typed in by hand. With a few hundred tags that is days of error-prone work. This converter does the address and data type mapping for you.

What it converts

Siemens address	Data type	Ignition, legacy syntax	Ignition 8.3 syntax
`%I0.3`	Bool	`[PLC1]IX0.3`	`[PLC1]IX0.3`
`%MW10`	Word	`[PLC1]MW10`	`[PLC1]MW10`
`%IW64`	Int	`[PLC1]II64`	`[PLC1]II64`
`%MD100`	Real	`[PLC1]MREAL100`	`[PLC1]MREAL100`
`%DB10.DBX2.1`	Bool	`[PLC1]DB10,X2.1`	`[PLC1]DB10.DBX2.1`
`%DB10.DBD4`	DInt	`[PLC1]DB10,DI4`	`[PLC1]DB10.DBDI4`
`%DB30.DBB0`	String[20]	`[PLC1]DB30,STRING0.20`	`[PLC1]DB30.DBSTRING0[20]`

German mnemonics (E, A, PEW), STEP 7 notation with spaces (MW 10) and WinCC-style addresses (DB10,DD4) are recognised as well. Data types map like this:

Siemens	Ignition
Bool	Boolean
Byte, USInt	Int2 (Short)
SInt, Char	Int1 (Byte)
Word, UInt	Int4 (Integer)
Int	Int2 (Short)
DWord, UDInt	Int8 (Long)
DInt, Time	Int4 (Integer)
Real	Float4 (Float)
LReal	Float8 (Double)
String[n]	String
Date_And_Time	DateTime

How to use it

Export the tags. TIA Portal: open the PLC tag table and use Export in its toolbar to save an .xlsx file. STEP 7 V5.x: in the Symbol Editor, choose Symbol Table, Export, and save as .SDF or .ASC. Any other list works too, as long as it has a name and a Siemens address column.
Add the device in Ignition. On the gateway, create a Siemens device connection (S7-300, S7-400, S7-1200 or S7-1500) with the same device name you enter in the converter. For S7-1200 and S7-1500, Ignition's documentation requires PUT/GET access to be permitted and optimized block access to be off for the data blocks you read.
Convert. Choose the target syntax, check the column mapping and read the notes column. Rows marked "to check" need a look before import.
Import and test. In the Ignition Designer, open the Tag Browser, choose Import Tags and select tags.json. Check a few values against the PLC before you build screens.

Which target to choose

Legacy syntax (DB10,DI4): the address format of Ignition's Siemens S7 drivers, documented for Ignition 8.1 and kept in 8.3 as the legacy drivers.
8.3 syntax (DB10.DBDI4): the absolute addressing format documented for the Siemens driver in Ignition 8.3.
OPC UA, symbolic (ns=3;s="Tag"): for S7-1200 and S7-1500 with the built-in OPC UA server enabled, and the way to reach optimized blocks. The namespace index is usually 3; check it with an OPC UA client and set it in the converter.

What it does not do

Data block members are not in TIA Portal tag tables. Address them from the DB, or use symbolic access for optimized blocks.
It creates plain OPC tags, not UDTs. A good UDT design is what keeps an Ignition project maintainable, and that is engineering work.
Screens, scripts, alarms and history are out of scope. That is where a migration takes time.

Migrating a whole system? We migrate Siemens WinCC and STEP 7 systems to Ignition with our own AI toolkit, which reads the old project and drafts tags, UDTs and Perspective views for our engineers to finish. See legacy SCADA migration or mail info@simsolutions.be.

Questions we get

Is the converter free?

Yes. No sign-up and no limits.

Is my tag list uploaded?

No. The page reads the file in your browser and builds the JSON there. Your data is not sent anywhere.

Which PLCs does it support?

S7-300, S7-400, S7-1200 and S7-1500, the families supported by Ignition's Siemens drivers. S7-300 and S7-400 use absolute addresses.

Does it work with WinCC tags?

Yes, if the export has a name and an absolute Siemens address column, as with WinCC V7 on the S7 channel, WinCC flexible or WinCC in TIA Portal. Map the columns after loading the file. Symbolic connections carry no absolute address; use the OPC UA option with the PLC tag names.

Why is a tag marked "to check"?

The converter flags rows where the data type is missing or does not match the address size, where a bit number is missing, or where peripheral I/O (PIW, PQW) was mapped to the process image. Check those before import.

Can you also convert our screens?

Screens, scripts and alarms are not a file conversion. We rebuild them in Ignition, with AI drafting and engineers finishing. Contact info@simsolutions.be.

Siemens to Ignition tag converter