Resolving PCS 7 V6.1 with STEP 7 V5.4: Compatibility Guide

1. The PCS 7 V6.1 / STEP 7 V5.4 Compatibility Problem

Siemens PCS 7 V6.1 is a tightly integrated process control system that bundles a specific STEP 7 version, hot-fix level, and component stack. The PCS 7 V6.1 media ships with STEP 7 V5.3, CFC V6.1 SP1, SFC V6.1 SP1, SIMATIC Net V6.3, and WinCC V6.0 SP3a. STEP 7 V5.4 projects cannot be opened in this environment because the S7 project file format and the underlying DLLs differ between V5.3 and V5.4. The PCS 7 installer registers COM components, ActiveX controls, and registry keys that collide with a parallel V5.4 STEP 7 install on the same Windows partition.

When you attempt to open a project programmed with STEP 7 V5.4 in PCS 7 V6.1, SIMATIC Manager reports Cannot open project / Unknown project version or The project was created with a newer version of STEP 7. The reverse case (PCS 7 V6.1 projects opened in stock STEP 7 V5.4) is also rejected because PCS 7 stores CFC and SFC chart objects that stock STEP 7 does not understand.

2. PCS 7 V6.1 Bundled Component Stack

The following table summarizes the engineering and runtime components delivered with the standard PCS 7 V6.1 image. The matrix is taken from the official PCS 7/505 OS Setup Guide (A5E00767200-01) and applies to the GA release as well as V6.1 SP1 / SP2.

Versions above the matrix are not generally compatible with PCS 7 V6.1. STEP 7 V5.4 SP4 alone has been observed to install cleanly in standalone mode, but it cannot be combined with PCS 7 V6.1 on the same Windows partition. WinCC V6.0 SP4 and Web Navigator V6.1 SP1 can be installed only with a customized PCS 7 install media; the customization procedure is described in section 6.

3. Why STEP 7 V5.3 and V5.4 Cannot Coexist on One Partition

STEP 7 installs shared libraries into system directories that are referenced by every subsequent STEP 7 component. A parallel install attempts to register conflicting versions of the same files. The most common conflict points are:

• S7hcomp.exe, S7hcomp_* – compiler used by all STL/FBD/LAD editors.
• SS7PCSV.EXE – PC/PG interface dialog.
• s7wb53ax.ocx, s7wb54ax.ocx – ActiveX controls used by HW Config and NetPro.
• SETUPEX.DLL – Siemens installer bootstrap shared by PCS 7 setup.
• Registry hive HKLM\SOFTWARE\Siemens\Automation\Step7 with version-specific subkeys.

Installing V5.4 over V5.3 in the same %ProgramFiles%\Siemens\Automation tree overwrites these files with V5.4 versions. The next time PCS 7 V6.1 launches HW Config, NetPro, or CFC, the ActiveX versions mismatch and the tools either refuse to start or crash when loading objects. Siemens does not support a partial version down-grade and explicitly documents that only one STEP 7 version per OS image is supported.

4. Solution A: Multi-Partition Installation

The recommended way to maintain two PCS 7 versions (and therefore two STEP 7 versions) on a single workstation is to install each version on its own Windows partition. The PC boots into the partition that matches the project you need to edit. A common field layout uses a 250 GB to 500 GB SATA / SSD disk split into four primary partitions:

1. Partition 1 — Windows 2000 SP4 + PCS 7 V6.0 SP3 (legacy projects).
2. Partition 2 — Windows XP SP2 + PCS 7 V6.1 SP2 (current production projects).
3. Partition 3 — Windows XP SP2 or Windows 7 32-bit + PCS 7 V7.0 SP1 (STEP 7 V5.4 projects).
4. Partition 4 — Data partition holding project archives (read/write from every OS).

Each Windows partition must be 32-bit. PCS 7 V6.x and V7.0 are not certified on Windows 7 / Server 2008 R2 64-bit and will refuse to install or behave erratically. PCS 7 V8.0 and later are the first releases with official 64-bit support.

Disk partitioning can be performed with the Windows Disk Management MMC, with a GParted live USB, or during Windows setup. Important constraints:

• Use a master boot record (MBR) partition table; PCS 7 V6.1 setup cannot read a GUID partition table (GPT).
• Set the active partition flag correctly before rebooting into each OS.
• Use a third-party boot manager (e.g., BootIt BM, GRUB4DOS) if you need a visible boot menu; the Windows bootloader can also be configured with boot.ini (XP) or bcdedit (Vista+) but does not always detect all partitions reliably.
• Disable Windows hibernation and Fast Startup; both write a hibernation file that can corrupt a partition shared with another OS.

5. Solution B: Virtual Machine Deployment

When physical partitions are not feasible, virtualization can host legacy PCS 7 images inside a Windows 7 / 10 / Server host. Field-proven options are VMware Workstation 6.5 to 12.x, VMware Player, and Oracle VirtualBox. Hyper-V is generally not recommended for PCS 7 V6.x because of COM-port and PC-Adapter passthrough limitations.

Recommended VM configuration:

• CPU: 2 virtual cores, VT-x / AMD-V enabled, Execution Cap 100%.
• RAM: 2 GB minimum for engineering, 4 GB for OS runtime with SIMATIC Batch.
• Disk: 40 GB fixed-size virtual IDE disk (SCSI disks are not certified for PCS 7 V6.1 setup).
• Network: Bridged adapter for direct connection to plant Ethernet; NAT for download-only scenarios.
• USB: Enable USB controller in EHCI mode and add individual device filters for the PC-Adapter USB or the CP 5711 / CP 5512.

6. Solution C: In-Place Upgrade Considerations

If the V6.1 projects can be migrated to a newer PCS 7 release, an in-place upgrade to PCS 7 V7.0 or later is the lowest-overhead path. PCS 7 V7.0 ships with STEP 7 V5.4 SP4 and can open projects originally programmed in V5.4. Migration must be performed in this order:

1. Run a complete project archive of the existing PCS 7 V6.1 project (.zip or .arc) and store it on the data partition.
2. Verify that the latest PCS 7 V6.1 hot-fixes (CFC HF9, SFC HF1, TH-IEA-PO HF2, SIMATIC Net V6.3 HF1, WinCC V6.0 SP4) are installed prior to the migration. Older projects cannot be migrated cleanly without these hot-fixes.
3. Insert the PCS 7 V7.0 DVD and choose Update installation. The installer upgrades STEP 7 to V5.4 SP4 and replaces CFC/SFC/WinCC in place.
4. Open the archived project in PCS 7 V7.0 and run the migration wizard. The wizard updates the project database, recompiles all CFC charts, and re-generates the WinCC pictures.
5. Verify each AS station compiles without errors and that the OS server reaches Server running state.

You cannot downgrade a V7.0 project back to V6.1 after the migration. The project database format is one-way. Always keep the original V6.1 archive in a read-only network share for the lifetime of the plant.

7. Hardware Replacement Scenario: CP 443-1EX11 → CP 443-1EX20

End-of-life CP 443-1 Ethernet modules are a common reason to evaluate STEP 7 V5.4. The CP 443-1EX11-0XE0 was discontinued and superseded by the CP 443-1EX20-0XE0. The EX20 adds IPv4 routing, NTP client, S7 communication via open TCP/IP, and a faster processor. From a PCS 7 perspective, however, the EX11 must be retained in the HW Config catalog of any V6.1 project that needs to remain on V6.1, because the EX20 cannot be configured in STEP 7 V5.3.

If a hardware failure forces a swap to the EX20 in a PCS 7 V6.1 plant, the practical choices are:

• Configure the EX20 as an EX11 in HW Config (Catalog > SIMATIC 400 > CP-400 > CP 443-1 > 6GK7443-1EX11-0XE0). The module boots and runs basic S7 communication because the lower-level firmware responds to the same SZL requests. NTP, IPv4 routing, and open TCP/IP features are not available.
• Migrate the project to PCS 7 V7.0 or later (see section 6) and configure the EX20 with its native GSD/EDD, then re-download the AS configuration.
• Replace the entire AS station with a modern CPU 410-5H and ET 200SP HA, which removes the CP 443 dependency entirely.

For projects that cannot be migrated, option 1 keeps the plant on PCS 7 V6.1 while restoring production with the EX20 hardware. Document the configuration override clearly in the plant asset register so the next engineer is aware that the EX20 features are disabled.

8. Hardware Configuration Workaround for Older PCS 7

The configuration override procedure is documented in the Siemens Knowledge Base under entry 31674579. The minimum steps to configure an EX20 as an EX11 are:

1. Open HW Config in PCS 7 V6.1 and insert a CP 443-1EX11-0XE0 in slot 4 of the UR2/UR2-H rack.
2. Open the CP properties and assign the IP address, subnet mask, and router that match the plant network. Disable AUI (the EX11 default), because the EX20 has no AUI port and will fail POST if AUI is enabled.
3. Set MAC address to Use ISO protocol only or to TCP/IP only depending on the existing plant segment. Both modes are supported by EX20.
4. Set Connection configuration > S7 connections to the same partner and partner port as the previous EX11. EX20 enforces the same TCP port 102 default.
5. Save, compile, and download the HW Config to the AS station. The EX20 will accept the configuration and the EX11 GSD profile.

9. PCS 7 Component Update Strategy

Selecting the right maintenance level is critical for long-term reliability. The following table summarises the recommended hot-fix matrix for PCS 7 V6.1 SP2. The values are derived from the official PCS 7/505 OS Setup Guide (A5E00767200-01) and Siemens Industry Online Support release notes.

Apply hot-fixes in the order listed in the matrix. A restart of the engineering station is required after each component update. Keep the original installation media in a write-protected location so the custom install can be rebuilt if needed.

10. Step-by-Step: Setting Up a Dual-Boot PCS 7 Environment

The following procedure produces a dual-boot workstation that can edit PCS 7 V6.1 (STEP 7 V5.3) and PCS 7 V7.0 (STEP 7 V5.4) projects from the same physical hardware.

1. Back up the existing PCS 7 V6.1 project archive to an external drive. Confirm the archive checksum.
2. Boot the existing Windows XP / Windows 7 image and defragment the system partition.
3. Insert a Windows 7 or Windows XP bootable media. From the Windows setup, choose Custom (advanced), then select an unallocated region of the disk. Create a primary partition of at least 60 GB and format it as NTFS.
4. Install Windows XP SP3 (or Windows 7 32-bit) on the new partition. Apply the latest service pack. Do not join a domain at this stage.
5. Install all required chipset and graphics drivers. Verify Ethernet connectivity.
6. Insert the PCS 7 V7.0 DVD and run the setup. Choose Complete installation with the engineering, OS server, and SIMATIC Net options.
7. Apply the hot-fixes for CFC HF7, SFC HF5, WinCC V6.2 SP2, and SIMATIC Net V6.4 in the order recommended by the PCS 7 V7.0 release notes.
8. Reboot into the original PCS 7 V6.1 partition. Verify that all PCS 7 V6.1 components still start. Do not run Windows Update on the V6.1 partition without first testing in a lab image; V6.1 is not certified on XP SP3 with certain .NET Framework 2.0 hot-fixes.
9. Configure the Windows boot manager (bcdedit or third-party) to default to the V6.1 partition with a 10-second timeout for selection.
10. Connect the CP 5711 / CP 5512 PC adapter and verify that PG/PC Interface shows the adapter on both partitions.
11. Open the archived V6.1 project in the V6.1 partition and verify all AS stations compile. Open the V7.0 example project in the V7.0 partition and verify the same.

11. Verification Procedures

After completing any of the installation paths above, run the following verification matrix. The checks are derived from the PCS 7 commissioning manual and the SIMATIC Manager online help.

Record the diagnostic buffer of each AS station after the first download and keep the log with the project archive. If any verification step fails, do not start commissioning; revert to the previous working image and apply the missing hot-fix.

12. FAQ