Configuring WinCC OS Simulation with S7-PLCSIM in SIMATIC PCS 7

In SIMATIC PCS 7 environments, simulating a WinCC Operator Station alongside S7-PLCSIM requires setting the logical device name of the WinCC communications channel to the appropriate PLCSIM driver instance, downloading hardware and CFC charts to the virtual controller, and initiating OS simulation from SIMATIC Manager. For TCP/IP connections, setting the WinCC Industrial Ethernet channel parameter to 'PLCSIM.TCPIP.1' enables bidirectional tag exchange and alarm testing on a standalone engineering station without physical controller hardware.

PCS 7 Virtual Simulation Architecture with S7-PLCSIM

SIMATIC S7-PLCSIM enables complete functional testing of PCS 7 automation software on a single PC by creating a software emulation of an S7-400 or CPU 410-5H controller. S7-PLCSIM executes standard controller code, including CFC, SFC, and user logic, without requiring physical CPU modules or field I/O racks.

To test operator faceplates, process graphics, and alarm messaging, the WinCC Operator Station (OS) must communicate with the S7-PLCSIM virtual backplane. Because WinCC ordinarily routes communication requests through physical CP 1613/CP 1623 cards or standard network interfaces using S7ONLINE, WinCC's communication driver parameters must be redirected to the PLCSIM software emulation layer.

Step-by-Step Procedure to Link WinCC and S7-PLCSIM

Follow this validated workflow to initiate concurrent AS and OS simulation:

Verify No Physical Connections: Disconnect any live plant network cables or ensure engineering occurs in an isolated project offline copy.
Launch S7-PLCSIM: In SIMATIC Manager, select the target AS station and click Options > Simulate Modules (or click the PLCSIM icon). The S7-PLCSIM window opens.
Select CPU Subnet Interface: In PLCSIM, verify the target interface matches your project (e.g., PLCSIM(TCP/IP) or PLCSIM(ISO)).
Download Hardware Configuration: In HW Config, click PLC > Download to transfer system data blocks (SDBs) to S7-PLCSIM.
Download CFC Program: In SIMATIC Manager, select the Charts folder and execute PLC > Download > Entire Program into PLCSIM.
Set Virtual CPU to RUN: In the S7-PLCSIM control panel, switch CPU state from STOP to RUN (or RUN-P).
Configure WinCC Logical Device: Adjust the WinCC channel unit parameters to target PLCSIM (detailed below).
Start OS Simulation: In SIMATIC Manager, right-click the OS project and select Start OS Simulation (or open the OS in WinCC Explorer and activate Runtime).

Configuring WinCC Communication Channels for PLCSIM

If WinCC fails to read process tags or displays disconnected 'yellow exclamation' symbols in faceplates, verify the channel unit settings:

Open the OS project in WinCC Explorer.
Expand Tag Management and navigate to SIMATIC S7 PROTOCOL SUITE.
Right-click the active protocol channel (e.g., TCP/IP or Named Connections) and select System Parameters.
Navigate to the Unit tab.
In the Logical Device Name drop-down menu:
- For Industrial Ethernet TCP/IP: Select PLCSIM.TCPIP.1.
- For Industrial Ethernet ISO: Select PLCSIM.ISO.1.
- For PROFIBUS DP: Select PLCSIM.PROFIBUS.1.
- For MPI: Select PLCSIM.MPI.1.
Click OK to save changes. If WinCC was already in runtime, deactivate and reactivate runtime to reload channel drivers.

PLCSIM Connection Types and Logical Device Settings

The following table summarizes the driver settings required for various WinCC communication channels when using S7-PLCSIM:

Project Connection TypeWinCC Channel SuiteWinCC Channel UnitLogical Device Name SettingPLCSIM Subnet ModeIndustrial Ethernet (TCP/IP)SIMATIC S7 PROTOCOL SUITETCP/IPPLCSIM.TCPIP.1PLCSIM(TCP/IP)Industrial Ethernet (ISO)SIMATIC S7 PROTOCOL SUITEIndustrial EthernetPLCSIM.ISO.1PLCSIM(ISO)PROFIBUS DPSIMATIC S7 PROTOCOL SUITEPROFIBUSPLCSIM.PROFIBUS.1PLCSIM(PROFIBUS)MPI BusSIMATIC S7 PROTOCOL SUITEMPIPLCSIM.MPI.1PLCSIM(MPI)Named Connections (Standard PCS 7)SIMATIC S7 PROTOCOL SUITENamed ConnectionsAuto-routed via S7ONLINESet PG/PC Interface to PLCSIM

Note: In standard PCS 7 architectures utilizing Named Connections with PC Station configured network adapters, changing the S7ONLINE access point in 'Set PG/PC Interface' to 'PLCSIM.TCPIP.1' allows seamless OS simulation without modifying WinCC channel properties.

Verification

Confirm successful OS and AS simulation connectivity:
1. In S7-PLCSIM, insert a variable view for an analog output (e.g., MD 100 or a DB variable connected to an APL block).
2. Force or modify the value within PLCSIM.
3. In WinCC Runtime, verify that the corresponding block icon and faceplate update immediately without communications disconnect symbols.
4. Execute an operator command from a WinCC valve or motor faceplate and confirm that the corresponding input bit changes state in S7-PLCSIM.

Limitations and Operational Precautions

Observe these critical operational rules when using S7-PLCSIM:
- Never Download to Real Hardware While Configured for PLCSIM: Always re-establish original network device parameters (e.g., CP_H1_1: or physical network card) in WinCC and compile OS changes prior to downloading to physical plant servers.
- Timing and Performance: S7-PLCSIM executes in non-real-time Windows cycles. Timers, cyclic interrupt OBs (OB30-OB38), and high-speed communication loops may execute at different speeds than physical S7-400 hardware.
- Redundancy Simulation: Standard S7-PLCSIM cannot simulate redundant S7-400H CPU synchronization or automatic hardware bumpless failover; simulation operates on a single virtual CPU instance.

Engineer FAQ

Why are tags showing grayed out with yellow exclamation marks in simulated WinCC?

This indicates communication failure. Ensure the virtual CPU in PLCSIM is in RUN mode and that the Logical Device Name under the WinCC S7 Protocol Suite matches the active PLCSIM interface (e.g., PLCSIM.TCPIP.1).

Can S7-PLCSIM simulate ALARM_8P messages?

Yes. S7-PLCSIM supports raw data communication and ALARM_8P message transfer, allowing full testing of WinCC AlarmControl displays and operator message acknowledgments.

Can I run two PLCSIM instances simultaneously in standard PCS 7?

Standard S7-PLCSIM V5.4 allows multiple instances (PLCSIM-1, PLCSIM-2), but cross-coupling communication between multiple virtual CPUs requires SIMIT or specialized simulation bridging tools.