What WinCC Unified is and where it comes from
For more than a decade, Siemens visualisation inside TIA Portal has been split into several products depending on the size of the application: WinCC Basic for Basic Panels, WinCC Comfort for Comfort Panels, WinCC Advanced for PC-based HMI and WinCC Professional for SCADA-type applications. Alongside them, outside TIA Portal, the classic WinCC V7/V8 SCADA line is still available.
WinCC Unified arrived with TIA Portal V16 (2019) with a different ambition: to merge that whole range into a single technology that works just as well for a 4" panel next to a machine as for a distributed SCADA system with several servers. To get there, Siemens did not evolve the Comfort/Advanced runtime; it built a new one on web standards. That decision explains almost every difference you will find and also why migrating is never a simple "save as".
If you need some background first, our guide on what an HMI is and how to choose the right panel covers the basics, and real-time SCADA explains where an HMI ends and a SCADA system begins.
Key differences at a glance
This table summarises the most relevant differences between WinCC Unified and its TIA Portal predecessor (WinCC Comfort/Advanced, with references to Professional where relevant):
| Aspect | WinCC Comfort / Advanced | WinCC Unified |
|---|---|---|
| Runtime technology | Classic proprietary runtime | Runtime built on web technologies (HTML5, SVG, JavaScript) |
| Panel operating system | Windows CE (Comfort Panels) | Linux-based SIMATIC Industrial OS (Unified Panels) |
| Graphics | Proprietary objects and bitmaps, fixed resolution | Scalable SVG vector graphics |
| Scripting | VBScript (C-Script in Professional) | JavaScript |
| Remote access | Sm@rtServer / WebNavigator with dedicated clients | HTML5 web client in any browser, no plug-ins |
| Faceplates | Functional but limited | Nested, more powerful faceplates that can open dynamically as pop-ups |
| Recipes | Classic recipes | Parameter sets |
| Logging | Files on the panel; SQL in Professional | Built-in SQLite on panels; Microsoft SQL Server on PC |
| Scalability | A different product for each level | One technology from machine panel to distributed SCADA |
| Roadmap | Mature platform, in maintenance | Where new Siemens features land |
Let us go through what actually matters in a project, point by point.
Native web architecture: the fundamental change
The core difference is architectural. In WinCC Unified, the screens you design in TIA Portal are compiled into standard web technologies and the runtime serves them to any compatible client. The operator panel, a control-room PC and the shift supervisor's tablet are, in practice, displaying the same application.
SVG vector graphics and scalable screens
Unified graphic objects are vector-based. A screen scales without pixelation when you move from a 7" panel to a 24" monitor, and you can import your own SVG symbols with dynamic properties (colours, visibility, rotation) bound to PLC tags. Unified also lets you design screens larger than the visible area and embed them in scrollable windows, which is very handy for large process overviews.
The trade-off: the classic Symbol Library from Comfort/Advanced does not exist in Unified. Symbols are replaced by Unified's industrial graphics library or by your own SVGs, and that has to be factored into any migration estimate.
HTML5 web client with no plug-ins
In Comfort/Advanced, remote access relied on Sm@rtServer (a mirror of the panel screen) or, in Professional, on WebNavigator. In Unified, web access is native: any modern browser opens the application as an independent client, with its own user and its own screen, with nothing to install. Even the new Unified Basic Panels include a web client out of the box.
It is a big step forward for maintenance and supervision, but it means taking network security seriously: segmentation, HTTPS with proper certificates and user management. We cover this in our article on industrial OT/IT cybersecurity.
JavaScript instead of VBScript
The change with the biggest day-to-day impact for HMI developers is the scripting language. Unified drops VBScript and adopts JavaScript, with its own object model to access tags, screens and alarms. The benefits are clear: a modern, widely used language, asynchronous execution, reusable modules and far more documentation available.
But it should not be underestimated. A Comfort VBScript does not translate line by line: events, the way tags are read and written, and function scope all change. In projects with a lot of script logic, the rewrite is the bulk of the migration effort. Our long-standing advice still applies: process logic belongs in the PLC, and the HMI should only display and request. The less script there is in the HMI, the cheaper any future migration will be.
Hardware: Unified Comfort Panels and Unified Basic Panels
WinCC Unified came with a new generation of hardware:
- Unified Comfort Panels (MTP series, 7" to 22"). The successors to Comfort Panels, with capacitive multi-touch screens, more processing power and the option to extend functionality with add-on apps.
- Unified Basic Panels (4" to 12"). The entry-level range, designed for simple machines and price-sensitive applications, but with the same Unified technology and a web client included.
- WinCC Unified PC Runtime. For operator stations and SCADA on industrial PCs or servers, covering the space previously held by WinCC Advanced and WinCC Professional.
One important detail: a Comfort Panel cannot be turned into a Unified Panel. They are different hardware and operating-system platforms (Windows CE versus SIMATIC Industrial OS), so migrating to Unified means replacing the panel. Also check the cabinet cut-out and power supply before ordering the new unit.
From machine to SCADA with a single project
Where Unified pulls furthest ahead of its predecessor is scalability. With Comfort/Advanced, if a machine grew to the point of needing SCADA features, you had to jump to another product with a different way of working. With Unified, the same technology covers everything from the machine panel to distributed client-server architectures, and screens can be reused across platforms with very few changes.
On top of that foundation, Siemens offers options that extend the runtime to match the project's needs:
- Collaboration: sharing screens and data between several Unified devices on the same line.
- Performance Insight: calculation and display of production KPIs such as OEE.
- Reporting and Audit: report generation and operator-action traceability, essential in regulated industries.
- Calendar and Sequence: time-based task scheduling and configurable operating sequences.
Unified also includes an OPC UA server, which makes it easier to connect visualisation with MES, ERP or IIoT platforms. If that layer interests you, read our OPC UA and Industry 4.0 guide. And if you are looking at SCADA alternatives outside the Siemens ecosystem, see our overview of Ignition SCADA.
What stays the same: TIA Portal remains at the centre
Not everything is new. WinCC Unified is configured inside TIA Portal, just like Comfort/Advanced, and shares tags, data types and alarm texts with the PLC without intermediate exports. System diagnostics, ProDiag and integration with the S7-1200 and S7-1500 all work within the same integrated environment.
On licensing, since TIA Portal V19 the WinCC Comfort, Advanced or Professional engineering licence can also be used to configure Unified, which removes a barrier to entry. Runtime licences, however, belong to different families and must be reviewed project by project.
Migrating from WinCC Comfort/Advanced to Unified: what converts and what does not
This is the question we are asked most often. The honest answer is that a Unified migration is more of an assisted re-engineering than an automatic conversion. TIA Portal helps carry part of the work over, but some elements have to be rebuilt:
| Element | What happens during migration |
|---|---|
| Tags and connections | Carried over fairly easily, especially with Siemens PLCs |
| Alarms | Carried over, although classes and texts are worth reviewing |
| Screens | Some objects convert; the layout is usually rebuilt to take advantage of SVG |
| VBScript code | Manual rewrite in JavaScript |
| Faceplates | Must be recreated using Unified technology |
| Symbol Library and ActiveX controls | Not available; replaced by SVGs or native Unified objects |
This is how we approach an HMI migration to Unified so that there are no surprises on site:
- Inventory of the current project. Number of screens, scripts, faceplates, recipes, third-party connections and remote-access functions. With that inventory, effort is estimated from data, not guesswork.
- A Unified library. Standard faceplates and SVG symbols for motors, valves, drives and alarms, reusable across all of the customer's machines.
- Review of script logic. Anything that is process logic moves to the PLC; only interface-specific behaviour stays in the HMI.
- Full office simulation. Testing against a simulated PLC before setting foot on site, validating screens, alarms and recipe changes.
- Commissioning during a planned stop. Panel replacement with the previous project backed up and ready to roll back if needed.
If the same machine also has an old PLC, this is the time to plan both migrations together. We explain how in migrating from S7-300 to S7-1500.
When does migrating to WinCC Unified make sense (and when not)?
There is no one-size-fits-all answer. These are the criteria we apply with our customers:
- New machine or line with a long service life: Unified, without hesitation. It is where Siemens concentrates development and the platform that will be supported the longest.
- Need for remote or multi-client access: Unified natively solves what required workarounds in Comfort/Advanced.
- Retrofit with a PLC replacement: use the shutdown to migrate the HMI as well and do it only once.
- Comfort Panel running fine, with spares and no new requirements: there is no rush, but it is worth planning. Keep a spare in stock and budget the migration for the next investment window. We discuss this in the importance of spare parts.
- A project with a lot of VBScript and no documentation: migrating costs more, but it also pays back more: it is the chance to clean up and document.
In our recent projects we already work with Unified by default. One example is the bottling line we automated with TIA Portal, where WinCC Unified serves the visualisation to line-side panels and to a browser for production managers.
WinCC Unified FAQs
Can I load a WinCC Unified project onto a Comfort Panel?
No. Classic Comfort Panels run a Windows CE-based runtime and cannot execute WinCC Unified, nor can they be converted with a firmware update. To use Unified you need a Unified Comfort Panel, a Unified Basic Panel or a PC running WinCC Unified Runtime.
Are VBScript scripts converted to JavaScript automatically?
Not reliably. Tags, alarms and a good share of the screens can be carried over with help from TIA Portal, but VBScript code has to be rewritten in JavaScript using the Unified object model. The same applies to faceplates, which must be recreated.
Do I need a new engineering licence for WinCC Unified?
Since TIA Portal V19, the WinCC Comfort, Advanced or Professional engineering licence can also be used to configure WinCC Unified. Runtime licences, however, belong to different families and must be reviewed for each project.
Does WinCC Unified also replace WinCC V7 or V8?
Not directly. WinCC V7/V8 is the classic SCADA line outside TIA Portal and is still available. WinCC Unified is the TIA Portal successor to WinCC Comfort, Advanced and Professional, and scales from the machine-level panel up to distributed SCADA systems.
Conclusion
WinCC Unified is far more than a facelift of WinCC Comfort/Advanced. Its web architecture, vector graphics, JavaScript and panel-to-SCADA scalability make it the foundation of Siemens visualisation for years to come. The price of that leap is a migration that requires rebuilding scripts, faceplates and much of the screen design, so it pays to plan it properly rather than wait until the old panel fails.
At Bluemation we develop and migrate WinCC Unified applications as part of our SCADA programming and PLC programming services, always designing the PLC and HMI as a whole. If you want to know what migrating your panels would involve, tell us about your installation and we will prepare a no-obligation estimate.