Auto-Start WinCC Flexible Runtime at Windows Boot for S7-314C

Overview

WinCC Flexible Runtime does not natively hook itself into the Windows boot sequence when installed on a desktop PC acting as the HMI workstation. After an unplanned power loss, the OS re-starts, but the HMI screen stays blank until an operator manually launches the project (.fwx) and clicks Start Runtime. For installations where a SIMATIC S7-314C-2DP (6ES7314-6CGxx-0AB0) is being visualised through a desktop PC over MPI, that intervention requirement defeats the purpose of an unattended machine. This reference covers four reliable methods for forcing WinCC Flexible Runtime to launch automatically at logon, plus the verification and recovery steps required to make the configuration robust against brown-outs and dirty shutdowns.

The official guidance is documented in the SIMATIC HMI WinCC flexible 2008 Runtime manual. Chapter 2 (Getting Started) describes the runtime executable and the recommended procedure for booting directly into a project without operator input. Keep that PDF open while commissioning, since the dialog names below reference its terminology.

SIMATIC HMI WinCC flexible 2008 Runtime - User Manual (PDF)

Prerequisites

How WinCC Flexible Runtime Boots

WinCC Flexible Runtime is a Win32 (or Win64 on newer builds) executable registered as a standard desktop application. It does not install a service, does not register a Boot Execute entry, and does not modify Winlogon by default. The intent is that most installations target a SIMATIC Panel PC (e.g. IPC277 or IPC477) where the CE / WinAC shell is configured to launch the runtime after boot. When the same runtime is repurposed onto a generic desktop PC, the operator must therefore provide the autostart hook manually.

Four mechanisms are supported, in order of troubleshooting preference:

1. Startup folder shortcut - visible, easy to remove, runs at user logon in the logged-in user's security context.
2. Registry Run key - runs at user logon (HKCU) or system logon (HKLM); invisible to most operators.
3. Scheduled task with delay - survives a fast successive reboot and tolerates slow MPI negotiation, which is a frequent issue after a hard power cycle.
4. WinCC flexible internal autostart - project property on the ES side that writes a boot entry into the registry at compile or transfer time.

Method 1 - Place a Shortcut in the Startup Folder

This is the simplest, most visible approach, and matches the recommended answer given in the runtime documentation. Locate the compiled runtime project file, then create a direct access (Windows shortcut) and drop it into the Startup folder of the user that owns the HMI session.

1. Open the directory holding the *.fwx project, e.g. D:\HMI\Line3\Start.fwx or C:\Program Files\Siemens\WinCC flexible\Runtime\Projects\Line3.fwx.
2. Right-click the *.fwx file, select Send to » Desktop (create shortcut).
3. Open the Windows Run dialog (Win+R), type shell:startup, and press Enter. This opens the per-user Startup folder.
4. Move or copy the shortcut from the desktop into the open Startup folder.
5. Reboot the PC and confirm the shortcut executes by checking Task Manager » Details » HmiRTm.exe (the runtime host).

To autostart Runtime for every user that logs on to the PC, use the machine-wide Startup folder instead:

shell:common startup

This resolves to %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup. Items placed here fire irrespective of which Windows account logs in, which is what an industrial PC typically wants.

Method 2 - Registry Run Key

For an invisible, unattended autostart that does not depend on the operator double-clicking a shortcut, register WinCC Flexible Runtime inside the Windows Run registry key. Two scopes are available.

Current user (HKCU)

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Run" ^
  /v "WinCCFlexibleRuntime" ^
  /t REG_SZ ^
  /d "\"C:\Program Files\Siemens\WinCC flexible\WinCC flexible Runtime.exe\" \"D:\HMI\Line3\Start.fwx\" /Run" ^
  /f

Local machine (HKLM)

reg add "HKLM\Software\Microsoft\Windows\CurrentVersion\Run" ^
  /v "WinCCFlexibleRuntime" ^
  /t REG_SZ ^
  /d "\"C:\Program Files\Siemens\WinCC flexible\WinCC flexible Runtime.exe\" \"D:\HMI\Line3\Start.fwx\" /Run" ^
  /f

Notes on parameter syntax:

• The /Run switch tells the launcher to start Runtime immediately and skip the project selection dialog.
• The leading " ... " pair around the executable path protects against spaces; the second quoted block is the project argument.
• Use reg delete from a CMD prompt with admin rights to remove the entry cleanly.

HKLM\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run

Method 3 - Scheduled Task with Startup Delay

A common failure mode after a brown-out is that the Runtime starts before the PC Adapter finishes negotiating with the S7-314C-2DP, producing an immediate "Connection interrupted" alarm. A scheduled task with a delay insulates Runtime from the worst of the noise during early boot.

1. Open Task Scheduler (taskschd.msc) and choose Create Task... (not the Basic Wizard).
2. On the General tab, name the task WinCC_Flexible_Runtime, tick Run with highest privileges, and select Run whether user is logged on or not.
3. On the Triggers tab, click New..., choose At startup, and tick Delay task for: » 30 seconds.
4. On the Actions tab, click New... and enter:

   Program:    "C:\Program Files\Siemens\WinCC flexible\WinCC flexible Runtime.exe"
   Arguments:  "D:\HMI\Line3\Start.fwx" /Run
   Start in:   "C:\Program Files\Siemens\WinCC flexible\"

5. On Settings, set If the task fails, restart every: to 1 minute with Attempt to restart up to: 3 times.
6. Confirm with the credentials of the operator account that owns the licence.

The 30-second delay gives the MPI driver and the S7-314C-2DP time to complete their initial handshake. The auto-restart setting recovers from any "Runtime was terminated unexpectedly" event during power-up.

Method 4 - Project-Side Autostart (WinCC flexible ES)

WinCC flexible ES has a project property that, when enabled, inserts an autostart entry on the engineering station as part of the "Transfer" step. This is convenient for engineers testing the same project on a development PC before promotion to the plant floor.

1. In the WinCC flexible project, open Project » Properties » Runtime.
2. Tick Start Runtime automatically when Windows starts.
3. Optionally tick Close project when Runtime exits to ensure no orphaned project remains in the editor.
4. Save the project, recompile, and transfer the project to the target runtime PC.

This method writes the registry key described in Method 2 for you. If the operator later disables Runtime from the project menu, the registry entry remains and a second boot will re-trigger Runtime with the previously compiled project - so verify the project file path is still valid after any rebuild.

Tying the Runtime to the S7-314C-2DP Connection

An autostart hook that does not establish the MPI link is only half a solution. Within WinCC flexible ES, configure the connection on the same PC that hosts Runtime.

1. In the project tree, right-click Connections and choose New Connection.
2. Set Communication driver to SIMATIC S7 300/400.
3. Set HMI station to S7-314C-2DP and pick the interface of the PC Adapter; for USB the entry is typically PC-Adapter (MPI).
4. In Set PG/PC Interface on the PC, choose PC Adapter (MPI) » Auto (or the explicit USB socket if you have several PC Adapters attached).
5. Set the MPI baud rate to 187.5 kbps for the S7-314C-2DP default; the dip switches on the CPU and the PC Adapter must both terminate and select the same baud rate.
6. Verify connectivity with Tools » Test Connection; a healthy link returns "Online" within 2 s.

Power-Loss Recovery and UPS Sizing

When the only practical answer to the operator is "reboot the HMI PC," an uninterruptible power supply closes the loop. Use the following sizing equation to estimate hold-up time:

t_holdup [min] = (battery_capacity_Wh * inverter_efficiency) / (load_W) * 60

Pair the UPS with Windows' built-in shutdown trigger so Runtime exits cleanly before the UPS drains. In Control Panel » Power Options » Change plan settings » Change advanced power settings, set Battery » Critical battery level » On battery: Shut down. This gives the scheduled task (Method 3) time to terminate Runtime gracefully; on the next power restoration, the PC reboots and Runtime comes up via the autostart hook without intervention.

Verification Procedure

After applying one of the methods above, prove the configuration with the following sequence.

1. Close WinCC Flexible Runtime if it is open.
2. Reboot the PC via Start » Power » Restart. Do not use the start menu's "Sign out" - only a full boot exercises the autostart hook.
3. After Windows settles, log in with the operator account.
4. Open Task Manager » More details and confirm HmiRTm.exe is present and consuming ~80-150 MB of RAM in the Processes tab.
5. Click into the Runtime window; the last-saved Runtime screen should be active within ~5 seconds of project load.
6. Pull a tag or write a known value through the Runtime to confirm the MPI connection to the S7-314C-2DP is live.

For Method 2 and Method 4, run regedit and confirm the entry survived the reboot. For Method 3, open Task Scheduler and inspect Last Run Result for the Runtime task; 0x0 indicates success.

Troubleshooting Matrix

Field-Proven Tips

• Don't combine methods. Having both a startup folder shortcut and a scheduled task pointing at the same .fwx will spawn two Runtime processes; the second one fails to bind the project port and the operator sees a blank screen. Pick one and stick to it.
• Document the project path. A surprising number of "Runtime won't start" tickets trace back to an engineer renaming a folder or moving the project to D:\Archive\... after commissioning. Pin the .fwx location inside the HMI documentation pack.
• Schedule periodic compile-and-restart. For shops running 24/7 with no weekly window, a 4 am Sunday reboot scheduled via Task Scheduler clears COM/DCOM leaks and gives the autostart hook a clean run.
• Keep the legacy MSI installer. WinCC flexible is end-of-life - new PC deployments on Windows 10/11 LTSC require SP5 plus the relevant Hotfix. Without the original installation media in a known location, recovery after a failed SSD becomes much harder.
• Use the engineering RS232 null-modem cable as fallback. The S7-314C-2DP serial port (X1) accepts a Siemens RS232 PC cable (6ES7901-2BF00-0AA0) which can be used to re-flash the project if both MPI and PROFINET are unavailable.

FAQ