Querying and Reporting Active Simulations (SimOn) Across SIMATIC PCS 7 Facilities

In SIMATIC PCS 7, querying and reporting all active block simulations (SimOn = 1) across a plant without inspecting charts individually is achieved using three standard diagnostic mechanisms depending on software release. In PCS 7 V8.2 and higher, operators and engineers can open the native 'Process Tag Browser' (Measuring Point Browser) in WinCC OS Runtime and filter by state 'Simulation' to generate an instantaneous plant-wide list. On the Engineering Station, Process Object View (POV) allows sorting the 'Parameters' tab by SimOn under live Test Mode or exporting to CSV. In legacy systems, logic can detect simulations by checking whether output signal status equals 16#60 (Simulated value).

Risks of Undetected Block Simulations in Operating Facilities

During commissioning, loop checking, and troubleshooting, automation engineers frequently activate the internal simulation functionality (SimOn = 1) on Advanced Process Library (APL) blocks—such as MonAnL, PIDConL, MotL, and VlvL—to bypass field transmitters and test software logic.

However, if active simulations are inadvertently left energized when a plant transitions into commercial production, the control system operates on static, fabricated numerical values rather than live process data. In continuous chemical and refining units, an unmonitored simulation on a high-level safety transmitter can lead to tank overfills or environmental excursions. Facilities require comprehensive, automated reporting tools to audit simulation states across tens of thousands of tags.

Diagnostic Audit Methods: Measuring Point Browser vs Process Object View

PCS 7 provides two primary native environments for querying simulation states without custom scripting:

Audit UtilitySoftware EnvironmentMinimum VersionEngineering Purpose & FeaturesProcess Tag Browser (Measuring Point Browser)WinCC OS RuntimePCS 7 V8.2+Runtime operator tool; filters by area, displays simulated tags, exports to print jobProcess Object View (POV)SIMATIC Manager (ES)All VersionsEngineering audit; filters parameters by SimOn, supports online test mode & CSV exportSignal Status Evaluation (#ST = 16#60)AS CFC Logic / WinCCAll VersionsAlgorithmic detection; triggers plant-wide 'Simulation Active' summary alarm

In modern facilities (PCS 7 V8.2, V9.0+), the Process Tag Browser is the most powerful runtime tool, requiring zero configuration.

Detecting Simulation States via Signal Status (16#60) in Legacy Systems

In facilities operating older versions (e.g. PCS 7 V7.1 or V8.1) where the Process Tag Browser is unavailable, APL blocks do not feature a dedicated boolean output pin named SimAct. However, APL adheres to strict NAMUR NE 107 signal status rules.

When a block transitions into simulation mode (SimOn = 1):

The block's output values (PV_Out, FbkRunOut, FbkOpenOut) have their accompanying Signal Status byte (#ST) forcibly set to 16#60 (Simulated value / manual value).
Engineers can extract this status using standard utility blocks:
- Connect the structured output (e.g., MotL.FbkRunOut) to the input of a StruDiIn (for digital) or StruAnIn (for analog) block.
- StruDiIn separates the structure into Value (BOOL) and ST (BYTE).
- Compare ST == 16#60 using a standard comparator block (CompAn02).
If any block evaluates ST == 16#60, energize a summary alarm or route the signal to an external message (ExtMsg1) to notify control room supervisors that simulated logic is active in that plant area.

Verification

Verify simulation audit capabilities through these operational checks:

Simulate a Test Block: On a test motor block (MotL), activate simulation mode (SimOn = 1).
Process Tag Browser Verification: Open WinCC OS Runtime. Click the Process Tag Browser icon on the toolbar. Select filter criteria: Status: Simulation. Confirm that MotL appears immediately in the results list.
Deactivation Check: Turn off simulation (SimOn = 0). Refresh the browser; confirm that the tag disappears from the active simulation inventory.

Limitations and Operational Precautions

When managing simulation states across production facilities, observe these operational guardrails:

Lock Simulation Authorizations: In WinCC User Administrator, restrict access to the 'Simulation' button on faceplates to Level 6 (Higher Process Controlling) or Level 7 (Engineering) to prevent standard operators from engaging simulations.
Shift Handover Audit Standard: Establish a standard operating procedure (SOP) requiring shift supervisors to generate a Process Tag Browser simulation report at every shift change.
Distinction Between Channel Simulation and Technological Simulation: Channel drivers (Pcs7AnIn) feature SimOn, and technological blocks (PIDConL) also feature SimOn. Ensure both levels are included in audit queries.

Engineer FAQ

Can the Process Tag Browser filter by specific plant areas?

Yes. The Process Tag Browser allows selecting individual technological areas (e.g., Unit 01, Boiler House) or auditing the entire plant simultaneously.

What does signal status 16#60 mean in PCS 7?

In Siemens APL signal quality standards, 16#60 indicates 'Good, Simulated', denoting that the value is syntactically valid but generated by internal simulation rather than a physical field sensor.

Can I force SimOn to 0 across the entire plant with one command?

In Process Object View, you can highlight all SimOn rows in the grid, change the value to 0, and execute a download changes to reset all simulations simultaneously.