Troubleshooting PLCSIM V13 SP1 Online Connection Errors in TIA

Troubleshooting PLCSIM V13 SP1 Online Connection Errors in TIA Portal

PLCSIM V13 and V13 SP1 ship as the integrated S7-1200/S7-1500 simulator for the SIMATIC TIA Portal engineering framework. When a workstation is upgraded incrementally, or when a project originally created in TIA Portal V12 is opened in V13 without a proper version migration, the simulator produces a small family of startup errors that prevent the virtual CPU from being reached. This reference documents the two error states most often reported after moving to PLCSIM V13 SP1, the root causes that generate them, and the field-proven procedure to bring simulation online again.

1. Problem Description

Two correlated symptom patterns are reported on the engineering workstation after a V13 → V13 SP1 update is applied, or when a TIA Portal V12 project is opened in V13 and simulation is started:

1. Error A — "PLCSIM not installed". The user invokes Start simulation from TIA Portal without first opening PLCSIM manually. The portal raises the dialog and refuses to launch the virtual S7-1200 / S7-1500 CPU.
2. Error B — "Simulation cannot be started because there is already an online connection to a device". PLCSIM is launched as a separate instance with a new project before Start simulation is triggered from TIA Portal. The portal refuses to take ownership of the already-open instance.

Either error terminates the simulation before the project is downloaded into the virtual PLC. When the engineer attempts to Download to device directly from the project tree, the wizard reports that no compatible target can be found, even though the PG/PC interface is configured to PLCSIM S7-1200/S7-1500.TCPIP.1.

2. Symptom Matrix

3. Root Cause Analysis

The combined symptoms above trace back to three independent but interacting root causes. Each must be confirmed before the field fix is applied.

3.1 Partial SP1 update across the TIA Portal stack

PLCSIM V13 SP1 must be installed at the same service-pack level as the TIA Portal host, the WinCC component (if HMI is present), Startdrive, and SIMOCODE ES. Per the official Siemens delivery note for the V13 SP2 generation, "The TIA Portal STEP 7 products (including PLCSIM), Safety, WinCC, Startdrive and SIMOCODE ES must be upgraded to the same version (V13 SP2)". The same rule applies to V13 SP1. When only PLCSIM is patched, the TIA Portal shell cannot locate the registered virtual-CPU service and the call to launch it fails with the "PLCSIM not installed" wording, even though the binaries are physically present on disk.

3.2 Doubled PLCSIM process holding the virtual adapter

PLCSIM V13 / V13 SP1 binds a single Windows TCP/IP interface entry (PLCSIM S7-1200/S7-1500.TCPIP.1) and a single default IP address (192.168.0.1). If a PLCSIM window is already open with its own project, a second Start simulation from the portal cannot acquire the adapter and reports the existing online connection. Closing the orphan instance is required before the portal can re-take ownership.

3.3 Mixed project / portal version (V12 project in V13 portal)

When a project created in TIA Portal V12 is loaded into V13, the portal offers an in-place upgrade. If the engineer continues with the original device-version containers and then attempts PLCSIM download, the portal will not find a downloadable V12 target on the V13 SP1 PLCSIM service. The matching device firmware version must be re-allocated to the V13 portal project before simulation can succeed.

4. PLCSIM V13 Architecture and Boundaries

PLCSIM V13 (and V13 SP1) is a user-mode Windows application that emulates an S7-1200 or S7-1500 CPU. It exposes a virtual Ethernet adapter that the TIA Portal PG/PC interface parameterizes as PLCSIM S7-1200/S7-1500.TCPIP.1, with IP 192.168.0.1 on subnet 255.255.255.0 by default. The supported instruction set, organisational blocks, and diagnostic behaviour are those of the matching firmware version declared in the TIA Portal project.

5. Prerequisites

Before applying the resolution, verify that the workstation carries a coherent TIA Portal V13 SP1 stack:

• SIMATIC STEP 7 Basic / Professional V13 SP1 (Update 4 or later recommended)
• PLCSIM V13 SP1, installed from the matching Siemens support package. Reference: Updates for PLCSIM V13 SP1 (Siemens Support, ID 109477180)
• If an HMI is part of the project: WinCC V13 SP1 in the matching flavour (Basic / Comfort / Advanced / Professional)
• If SINAMICS drives are present: Startdrive V13 SP1
• If safety logic is used: SIMATIC Safety V13 SP1
• Administrator rights on Windows 7 SP1 / Windows Server 2008 R2 (or later supported OS for the SP1 generation)

All components must be patched to the identical service-pack level. Partial patching is the most common cause of the symptom cluster described in Section 1.

6. Step-by-Step Resolution

Apply the following sequence. Each step has a deterministic pass/fail check that should be confirmed before moving to the next step.

1. Inventory the installed TIA software. Open Start → Control Panel → Programs and Features (Windows 7/Server 2008 R2) and record every Siemens entry. The version column must read V13.0 + SP1 for STEP 7, PLCSIM, WinCC, Startdrive, SIMOCODE ES, and Safety.
   Pass: All entries show identical SP level.
   Fail: Patch the missing components from the Siemens support portal before continuing. Do not skip this step.
2. Close every orphan PLCSIM window. Use Task Manager → Details to confirm that no S7PLCSIM.exe instance is running. Right-click → End task for any remaining entry.
   Pass: No S7PLCSIM.exe process listed.
3. Verify the PG/PC interface assignment. Open Start → SIMATIC → PG/PC Interface (the 32-bit applet, even on 64-bit Windows). Set the access point S7ONLINE to the parameterization PLCSIM S7-1200/S7-1500.TCPIP.1. Click Diagnostics and confirm that the virtual adapter reports OK on address 192.168.0.1.
4. Open TIA Portal only — do not start PLCSIM manually. Launch the TIA Portal V13 SP1. Open the target project. Select the PLC device in the project tree. From the toolbar invoke Start simulation (the play icon on the Online menu). The portal will instantiate PLCSIM and download the project automatically.
   Pass: PLCSIM window opens automatically and the green RUN/STOP LED on the simulated CPU transitions to RUN after download completes.
   Fail (Error A still appears): Component registration is broken. Re-run the PLCSIM V13 SP1 setup in Repair mode, then reboot.
5. If the project originated in TIA Portal V12, complete the device-version upgrade (Section 7) before retrying Step 4.

7. Upgrading a TIA Portal V12 Project to V13

When a V12 project is opened in V13, the portal prompts for a project upgrade. The PLC device containers, however, retain their V12 device firmware references and must be re-allocated to a V13 firmware before PLCSIM V13 SP1 will accept the download.

1. In TIA Portal V13 SP1, open the upgraded project. The portal will display the Project upgrade dialog on first open — click Yes to commit.
2. Navigate to the Project tree → PLC → Device view. For every PLC device in the project, right-click and select Change device / version (or Change device → Device version depending on the SP1 build).
3. In the dialog, choose the V13 (or V13 SP1) firmware article number for the matching CPU. The article number must correspond to a device version installed by the TIA Portal V13 SP1 hardware catalog. Click OK to commit.
4. Repeat the change for the HMI devices, drives, and any other station, using the matching V13 SP1 catalog entries. The HMI runtime is not required for PLCSIM-only simulation, but a clean version alignment is required to compile the project.
5. Compile the project (Project → Compile all). Resolve any residual type mismatches introduced by the firmware change (e.g. optimized-block tag access on S7-1500 must be honored by all clients).
6. Return to Section 6, Step 4, and start the simulation from the portal without manually opening PLCSIM.

8. PG/PC Interface Configuration Reference

The PLCSIM V13 virtual adapter is the only parameterization that allows TIA Portal to reach a simulated S7-1200 / S7-1500. The following settings are mandatory:

If a previous install assigned a real Ethernet NIC to S7ONLINE, simulation cannot be reached. Reset the assignment to PLCSIM S7-1200/S7-1500.TCPIP.1 in the PG/PC interface applet. The change is effective immediately and does not require a Windows reboot.

9. HMI Simulation — What PLCSIM Will Not Do

PLCSIM V13 SP1 does not provide an HMI runtime. If the project contains a Comfort Panel, KTP, or a PC-based HMI, the engineer must install and use one of the following:

• WinCC Runtime Advanced V13 SP1 for KTP / Comfort / WinCC RT Advanced targets
• WinCC Runtime Professional V13 SP1 for PC-based SCADA targets
• The bundled Start simulation on the HMI device in TIA Portal, which uses the WinCC RT simulator (not PLCSIM) to run the panels against the running PLCSIM PLC instance

The recommended workflow for combined PLC + HMI simulation in TIA Portal V13 SP1 is:

1. Start PLCSIM from the portal (Section 6, Step 4). The simulated PLC is now online.
2. Right-click the HMI device in the project tree and select Start simulation. WinCC RT starts, establishes a connection to the PLCSIM CPU over the virtual adapter, and the panels become operable.
3. For WinCC Professional panels with tags served by the simulated S7-1500, the connection in the HMI configuration must reference the simulated CPU's IP 192.168.0.1 with the slot configured for the S7-1500 (slot 1 for the CPU, slot 0 for the PN interface).

10. Verification Procedure

After applying the resolution, perform the following checks in order. Each must pass before declaring the workstation healthy.

1. PLCSIM launches from the portal. Click Start simulation on the PLC. PLCSIM V13 SP1 window appears within 5–10 seconds. No "PLCSIM not installed" dialog appears.
2. Project downloads into the virtual CPU. The status bar of the TIA Portal reports Download to device completed without errors. The simulated CPU transitions from STOP to RUN with the green LED active.
3. Online connection is exclusive. Open Online → Accessible nodes. The simulated CPU is listed once, on 192.168.0.1, with the configured PROFINET device name. No duplicate entries are shown.
4. Watch table operates. Create a watch table with one tag from the user program, force the value, and confirm the value changes in the simulated CPU using Monitor / modify.
5. HMI simulation (if applicable). Right-click the HMI device and select Start simulation. The WinCC RT panel opens and reads tags from the simulated PLC.

11. Field Troubleshooting Matrix

The matrix below maps the most common error patterns reported against PLCSIM V13 SP1 installations to their root cause class and the corrective action. Use it as a triage aid when the symptom description in Section 1 does not match exactly.

12. Preventive Checklist

Apply the following controls to the engineering workstation image to prevent recurrence of the symptom cluster:

• Maintain a single source of truth for the TIA Portal patch level. Whenever a Siemens update is applied, patch STEP 7, PLCSIM, WinCC, Startdrive, SIMOCODE ES, and Safety in the same maintenance window.
• Use the Siemens Automation License Manager to inventory installed software and to verify the SP level across packages.
• Do not open PLCSIM manually as a workaround. The portal-driven Start simulation is the only supported entry point on V13 SP1.
• When migrating a V12 project, perform the device-version change for every CPU and HMI in a single session, then save the project as a V13 SP1 project. Do not retain a V12 backup as the live working copy.
• Document the PG/PC interface assignment in the workstation handover. PLCSIM S7-1200/S7-1500.TCPIP.1 is the only correct value for SIMATIC S7ONLINE during simulation; restore it after any other engineering work that re-assigns S7ONLINE to a real NIC.

13. Related References and Official Sources

For deeper background on the TIA Portal V13 / V13 SP1 component compatibility matrix and the V13 SP2 trial delivery, refer to the following Siemens support entries. These are the only sources that authoritatively describe which packages must be co-installed and at which service-pack level.

• Updates for PLCSIM V13 SP1 (Siemens Support, ID 109477180) — incremental update installers for PLCSIM V13 SP1 and prerequisites.
• SIMATIC STEP 7 including PLCSIM V13 SP2 TRIAL Download (Siemens Support, ID 109745155) — version alignment rule: "The TIA Portal STEP 7 products (including PLCSIM), Safety, WinCC, Startdrive and SIMOCODE ES must be upgraded to the same version (V13 SP2)". The same principle applies to V13 SP1.