WinCC Flexible RT: Configuring PC Runtime from MP 377 Projects

WinCC Flexible RT: Configuring PC Runtime from MP 377 Projects

Siemens WinCC flexible supports a development workflow in which a single HMI application is authored once in the engineering station and then deployed against multiple runtime targets, including Siemens operator panels (OP/TP/MP) and the WinCC flexible Runtime (RT) software on a standard PC. The same HMI program is reusable across the MP 377 family, Comfort Panels, and PC-based visualization, provided the target device is reselected in the project tree and a matching runtime license is installed on the PC. This reference explains how to architect a project that runs part of the HMI logic on the panel and a separate, smaller visualization on a remote PC, and how to keep the two projects synchronized over Ethernet.

1. WinCC Flexible Runtime Architecture Overview

WinCC flexible Runtime is the PC-resident execution environment that interprets a compiled WinCC flexible HMI project the same way a panel would. The WinCC flexible 2008 Runtime manual (ID 18795593) documents the supported target platforms, the licensing model, and the behavior differences between panel and PC runtimes.

The compiled HMI project is identical in structure regardless of the runtime target. What changes between an MP 377 and a PC RT is the set of device-specific properties (screen resolution, key/softkey count, available system functions, fonts, available printer drivers, available archives) and the licensing dongle or soft-key mechanism that protects the runtime image.

2. Licensing Model and Product Variants

WinCC flexible 2008 Runtime ships in several variants that determine which panel image can be emulated and which features are unlocked. The two relevant to a mixed OP/PC deployment are:

3. System Requirements for the PC Runtime Host

The minimum hardware and software requirements for WinCC flexible 2008 RT on a Windows PC are documented in the runtime manual and summarized below.

4. Project Strategy: One Project vs. Two Projects

WinCC flexible allows you to compile a single project for a single target device. While the screens, tags, scripts, and alarms can be reused, the device properties (resolution, key layout, available system functions, key shortcuts) are bound to the selected target. There are two valid strategies:

4.1 Single project, multiple target images

You maintain one .hmi project. You open it with WinCC flexible ES, change the target device in the project tree, recompile, and transfer the resulting runtime image to either the MP 377 or the PC RT. This works well for small projects where the panel and the PC run the same screens.

4.2 Two separate projects (recommended for partial replication)

When only a subset of the screens is needed on the PC (e.g., 2 of 5 sections), Siemens recommends a copy-then-trim workflow:

1. Author and validate the full project against the MP 377 target.
2. Use File > Save As to produce a second .hmi file under a new name (e.g., Plant_RT.hmi).
3. In the copy, change the target device from the MP 377 to PC Runtime in the project tree.
4. Remove or hide the screens, tags, alarms, and scripts that are not required on the PC.
5. Adjust device-specific objects (softkeys, system diagnostic windows, key shortcuts) to the PC layout.
6. Compile to the PC Runtime target and transfer to the RT host.

5. Step-by-Step: Building the MP 377 Project

Author the master project against the panel that physically exists on the line. For this guide the target is a Siemens MP 377 12" Touch Key, but the same workflow applies to MP 277, TP 177, OP 277, or any Comfort Panel.

1. Start WinCC flexible 2008 ES and select Create a new project > Single project.
2. Select the device: choose the exact panel model (e.g., MP 377 12" Touch) in the dialog. The model selection defines the screen resolution, key matrix, and supported system functions.
3. Configure the PLC connection: in the project tree, right-click Connections > New Connection. Choose the controller (S7-300/400 via PROFINET or MPI, S7-1200/1500 via Ethernet, S7-200 via PPI, or a third-party Modbus controller). Configure the address, rack, slot, and cycle time.
4. Define tags: under Tags, add the external tags pointing at the PLC. Use a consistent naming scheme (e.g., DB100.DBD0 for analog values, DB100.DBX0.0 for booleans). Configure the acquisition cycle and the limit ranges.
5. Build screens: in the Screens editor, create the process screens, faceplates, and trend views. Use the device-specific palette to keep navigation buttons and softkey assignments consistent with the MP 377 key layout.
6. Wire alarms and scripts: define the discrete alarms, the analog alarms, and the VB-Script routines that perform value calculations. Note each script's target context (panel vs. PC) for later adjustment.
7. Compile and simulate: select Project > Compiler > All and start Runtime Simulator with project to validate the project before transferring it to the physical panel.
8. Transfer to MP 377: connect the panel to the engineering PC via Ethernet (or MPI/PROFIBUS), enable Transfer mode on the panel, and use Project > Transfer > to target device.

6. Step-by-Step: Building the PC Runtime Project

Once the MP 377 project is stable, fork a copy for the PC runtime and adapt it. This is the workflow that directly answers the question of running only part of the HMI logic on a remote PC.

1. Copy the project: in WinCC flexible ES, open the MP 377 project and select File > Save As. Save the file as Plant_RT.hmi in a new folder.
2. Change the target device: in the project tree of the copy, right-click the device name and select Change device > PC Runtime > WinCC flexible RT. The screen resolution, key matrix, and device palette are automatically updated.
3. Resize and adjust screens: most MP 377 panels are 800 x 600 or 1024 x 768. PC runtimes are typically 1920 x 1080. Re-layout screens that depended on the panel resolution. The Adapt to new size option in the Screens editor accelerates this.
4. Strip unused screens: remove the screens that should not appear on the PC. The remaining screens can be reorganized into a smaller navigation tree.
5. Convert panel-specific objects: replace panel-only system functions (e.g., SetLanguage limited to the panel's installed languages, System diagnostic on PROFIBUS-specific panels, FunctionKeyAssignment) with PC equivalents. The Project > Compiler > Consistency check tool flags unsupported calls.
6. Adjust VB scripts: any script that references HMIRuntime.Screens paths, panel-specific file system paths, or panel-only ActiveX controls must be revised. See section 7.
7. Configure the PC connection: in the PC project, the connection to the PLC uses the PC's Ethernet adapter. Enter the PLC's IP address and rack/slot. If the PC and the MP 377 must both exchange data (PC acting as a secondary viewer), add a connection to the panel as well.
8. Compile for PC RT: select Project > Compiler > Generate Runtime files. The output is a .fwx runtime image and a set of support files.
9. Transfer to the PC: copy the runtime files to the PC and start the WinCC flexible RT Loader. Click Settings, point to the .fwx, and enable Autostart on boot. The runtime image is loaded into the RT service.

7. VB Script Adaptation for PC Runtime

VB Script in WinCC flexible is interpreted identically on the panel and the PC, but several runtime objects behave differently. The most common adjustments when moving a project from MP 377 to PC RT are:

When a project is built for both targets, the recommended pattern is to wrap device-specific calls in conditional branches that test the active target, e.g.:

Dim sPath
If HMIRuntime.BaseScreenName = "" Then
  ' PC runtime: use Windows path
  sPath = "C:\PlantData\Logs\"
Else
  ' Panel: use storage card
  sPath = HMIRuntime.FileSystem.Path & "\Logs\"
End If

8. Ethernet Topology: MP 377, PC RT, and PLC

Three common topologies are used for a parallel panel + PC RT deployment.

8.1 Independent viewers on the same PLC

The MP 377 and the PC RT both establish a separate S7 connection to the PLC. They do not communicate with each other. This is the simplest and most resilient setup. Both viewers see the same process values; either one can be offline without affecting the other.

  +---------+        +---------+        +---------+
  | MP 377  |        | PC RT   |        |  S7 PLC |
  | (HMI)   |--------| (HMI)   |--------| (CPU)   |
  | eth0    |        | eth0    |        | eth0    |
  +---------+        +---------+        +---------+
        \________ 192.168.0.x /24 _________/

8.2 PC RT as a passive remote viewer

The PC RT connects to the MP 377's SMART Server over HTTP, and the MP 377 forwards the screens to the PC. The PC does not need a direct PLC connection. This is useful when the PC is in a remote office and the panel is the only authorized PLC client.

8.3 PC RT as a data sink

The PC RT runs as a viewer; an additional service on the PC (e.g., a WinCC flexible archive database or a custom VB script) writes the tag values to disk for reporting. The PC is on the same Ethernet segment as the MP 377 and the PLC.

9. Configuring the Ethernet Connection on the PC RT

1. Set a static IP on the PC's Ethernet adapter (e.g., 192.168.0.50 / 255.255.255.0). Avoid DHCP for an operator PC.
2. Verify reachability with ping to the PLC (192.168.0.10) and to the MP 377 (192.168.0.20).
3. In the WinCC flexible RT Loader, click Settings > Connections and confirm the active connection to the PLC is bound to the correct adapter.
4. For S7-300/400 PROFINET, the access point used by the S7 driver is S7ONLINE; for S7-1200/1500 it is SIEMENS TCP/IP. The Set PG/PC Interface tool on the PC must point at the correct driver and access point.
5. Restart the WinCC flexible RT Loader service. The runtime image reloads and the new connection is established.

10. Verification Checklist

Before declaring the dual-target deployment ready for production, perform the following checks. Each item has a pass/fail result and a corrective action.

11. Troubleshooting Matrix

12. Migration Path to TIA Portal

WinCC flexible 2008 is a legacy engineering tool, but it is still in service on many lines. New projects should be authored in TIA Portal with WinCC (TIA) / WinCC Unified, which offers a more modern PC runtime (WinCC Runtime Professional) and a more flexible target selection. The WinCC flexible project converter in TIA Portal will translate a .hmi project into a TIA Portal project, but manual review is required for panel-specific calls and scripts. Until migration, the dual-target workflow described in this guide remains the recommended approach for combining an MP 377 with a PC RT.

13. Field-Proven Recommendations

• Version-lock the engineering environment. Keep the same WinCC flexible SP level on every engineering PC and the same RT SP on every runtime PC. Mismatched SP levels cause compile-time warnings that behave differently on different targets.
• One source of truth for tags. Generate the tag list from the PLC symbol table (export to .sdf or use the TIA Portal export) and re-import it into both projects to keep the two builds synchronized.
• Isolate the control LAN. A dedicated Ethernet segment for HMI/PC/PLC traffic prevents broadcast storms and Windows update reboots from interrupting visualization.
• License the PC RT explicitly. Don't assume a development license is sufficient for production. Procure a runtime license and key it to the operator PC before commissioning.
• Document the device target switch. A simple text file or a project header comment that records which target the project is currently built for prevents deployment confusion in maintenance windows.
• Test scripts in simulation first. Use the Runtime Simulator with project feature in WinCC flexible ES to validate scripts before transferring to either the panel or the PC.

FAQ