Migrating WinCC V6.0 SP4 to V7.x for S7-400 Communication

1. WinCC V6.0 SP4 Lifecycle Status and Migration Context

SIMATIC WinCC V6.0 SP4 is a legacy SCADA release whose delivery cycle closed years ago. Per the official Siemens delivery release SIMATIC WinCC V6.0 SP4 - Delivery Release (ID 22450372), V6.0 SP4 superseded its immediate predecessor as a separate product and full version, and has itself since been superseded by WinCC V6.2, V7.0 SP2, V7.3, V7.4, V7.5, and the modern TIA WinCC family. Attempting to commission a V6.0 SP4 backup on a current PC platform is therefore a migration problem, not an installation problem.

Two constraints dominate the migration plan:

• License availability. WinCC V6.0 SP4 has been withdrawn from sale. New licenses must be obtained for the current version, and the path through Siemens will involve either (a) a current WinCC license exercised against a legacy project under downgrade terms, or (b) repurchase of WinCC Runtime/Configuration at the current catalog number.
• Operating system and SQL server. V6.0 SP4 is locked to Windows XP Professional SP1a/SP2 and Microsoft SQL Server 2000 SP4 per the WinCC V6.0 SP4 Compatibility Notes (PDF, 12/2005). A migration off Windows XP is mandatory for any modern hardware lifecycle.

The recommended target is WinCC V7.5 SP1 or later, which preserves the V7 project structure and accepts a direct migration from a V6.x backup via the WinCC Project Migrator.

2. Prerequisites for a Successful Migration

Before opening the V6.0 SP4 backup file, confirm the following prerequisites on the engineering workstation that will host the target installation.

3. License Acquisition Strategy

Because V6.0 SP4 is no longer orderable, the procurement path is one of the following:

1. Downgrade right from a current WinCC V7.x license. If a higher WinCC version is licensed, Siemens historically permits use of the software on a lower version as long as both versions are covered under the active license contract. Contact the local Siemens representative with the certificate number and request written confirmation that V6.x runtime is permitted.
2. Repurchase current WinCC V7.5 SP1 license bundle. Order the WinCC V7.5 SP1 PowerPack or full version. Typical catalog numbers (verify with Siemens Industry Mall at order time):
   • 6AV6371-1CA07-5AX0 - WinCC V7.5 SP1 RT 128 PowerPack
   • 6AV6371-1CB07-5AX0 - WinCC V7.5 SP1 RT 512 PowerPack
   • 6AV6371-1CD07-5AX0 - WinCC V7.5 SP1 RT 2048 PowerPack
   • 6AV6381-2AA07-5AX0 - WinCC V7.5 SP1 Configuration
3. Transfer a previously used V6.0 SP4 license. If the original license dongle or ALM license exists from the original installation, it can be migrated through the Automation License Manager to a new host. The transferred license is still tied to the V6.x feature set and will not unlock V7.x features.

For pricing and availability of any catalog number above, request a quote from the local Siemens Industry Online Support portal or Industry Mall; the support team will not publish list prices for older or current WinCC releases in public forums.

4. Operating System and Software Stack Compatibility

The compatibility envelope is the dominant technical constraint. The V6.0 SP4 Compatibility Notes PDF referenced above specifies the following for the legacy release:

Migrating directly from V6.0 SP4 to V7.5 SP1 bypasses the SQL 2000 dependency entirely because WinCC migrates the project database (and converts it to the newer SQL Server format) as part of the project migration wizard.

5. Migration Path: V6.0 SP4 to V7.x

Two valid paths exist. The intermediate path (V6.0 SP4 to V7.0 SP2) is sometimes required when the original project uses V6-only C scripts or V6-only graphics object types that were retired before V7.4.

1. Direct path (recommended): V6.0 SP4 backup → V7.5 SP1 via the Project Migrator. The Project Migrator handles the script API translation, graphics refactor, and database upgrade in one pass.
2. Intermediate path: V6.0 SP4 backup → V7.0 SP2 → validate → V7.5 SP1. Use this when custom VB or C scripts reference APIs that were deprecated between V7.0 SP2 and V7.4.

Step-by-step for the direct path:

1. Install WinCC V7.5 SP1 from the official DVD/ISO. Allow the bundled SQL Server install to complete. Reboot.
2. Open WinCC Explorer on the new installation. Do not import the V6.0 SP4 backup into a running WinCC project on a V6 host; always migrate on the target version.
3. Select File > Migrate Project. Point to the V6.0 SP4 backup directory (the directory containing the .mcp file plus subfolders "GraCS", "Library", "PRT", "SCRIPT", etc.).
4. The Project Migrator reports a compatibility report. Confirm that no hard errors are reported. Warnings about deprecated scripts and pictures can be acknowledged; resolve them after migration.
5. Run the migration. Expected duration: 5-30 minutes for a typical 2,000-tag single-station project; up to several hours for multi-server or large archive projects.
6. Open the migrated project. Validate graphics, scripts, archive tags, and alarms in a controlled offline test before connecting to the live PLC.

6. CP 5611 PROFIBUS Communication with S7-400

The CP 5611 (6GK1 561-1AA01) is a PCI card that provides PROFIBUS DP and MPI master capability on a PC. For an S7-400 connection it is the classic, low-cost PROFIBUS interface. The newer CP 5621 (PCIe, 6GK1 562-1AA00) is electrically and functionally compatible and recommended for any new build because PCIe slots are standard on current PCs.

Installation sequence:

1. Power down and install the CP 5611/5621 in a free PCI/PCIe slot. Apply the slot bracket screw.
2. Boot the PC. Open Device Manager and confirm the card is enumerated under "Siemens AG, SIMATIC NET" with no yellow bang.
3. Install the matching SIMATIC NET version (e.g., V16.1 for WinCC V7.5 SP1 on Windows 10 LTSC). The installer places the PG/PC interface configuration utility.
4. Open Set PG/PC Interface (Start > Siemens Automation > SIMATIC NET > Set PG/PC Interface). Create a new access point: S7ONLINE_SETPG mapped to CP5611.PROFIBUS.1 for PROFIBUS, or to CP5611.MPI.1 for MPI.
5. Insert the CP 5611/5621 into the PROFIBUS segment terminated with 220 Ω at both ends (the card itself provides a 9-pin D-sub female PROFIBUS connector; on-board termination is generally off, so external terminating resistors are mandatory).
6. On the S7-400, confirm the CPU's PROFIBUS interface is enabled in STEP 7 (HW Config) and that the S7-400 PROFIBUS address is set (default 2). Note: S7-400 CPUs with integrated PROFIBUS DP (e.g., CPU 412-2, 414-3, 416-3) need no additional CP module for PROFIBUS.

7. WinCC Channel Configuration: SIMATIC S7 Protocol Suite

WinCC reaches the S7-400 via the SIMATIC S7 Protocol Suite channel. Add it under Variable Management > Add New Driver > SIMATIC S7 Protocol Suite. The channel unit selection depends on the physical path:

To configure a PROFIBUS connection:

1. Right-click PROFIBUS in the channel tree and select New Connection.
2. Open the connection properties. Set the S7-400 address (rack/slot default 0/2, but match the configured PROFIBUS node). Maximum PDU size defaults to 240 bytes for S7-400.
3. Create tags. Map WinCC tags to the S7 data blocks using standard addressing:
   • Bit: DB100.DBX0.0
   • Byte: DB100.DBB1
   • Word: DB100.DBW2
   • DWord: DB100.DBD4
   • Real: DB100.DBD8 with data type FLOAT
4. Set acquisition mode: Cyclic on demand for control tags, Cyclic continuous for process values, default cycle 1 s for slow processes, 250 ms or 500 ms for fast machine states.
5. Save and compile the channel. WinCC will create the connectivity tree for the runtime database.

8. Industrial Ethernet Alternative: TCP/IP Channel via CP 443-1

If the S7-400 has a CP 443-1 (e.g., 6GK7 443-1EX20-0XE0 for 100 Mbps or 6GK7 443-1GX20-0XE0 for Gigabit) installed, the PROFIBUS layer can be skipped entirely. Connect the CP 443-1 and the PC to the same Ethernet switch; configure an S7 connection in STEP 7 NetPro; then add the TCP/IP channel unit in WinCC with the CP 443-1 IP address, rack 0, slot 0 (the CP's slot, not the CPU slot). This is the recommended path for any new migration because it avoids the legacy CP 5611 hardware lifecycle.

9. Runtime Verification and Acceptance Test

Before connecting the migrated runtime to the live process, execute the following acceptance test in offline or simulation mode:

1. Open the migrated project and start Runtime. Confirm no licensing alarms in the WinCC Alarm Logging (alarm class "System, License").
2. Use the WinCC Channel Diagnosis (Start > Siemens Automation > WinCC > Tools > Channel Diagnosis). Verify the channel state is "Connected" for each configured connection.
3. Use SIMATIC Manager > PLC > Monitor/Modify on the S7-400 side to toggle a known bit (e.g., M0.0). Observe the WinCC tag value updating in the tag management online display.
4. Force a known value into a DB word from STEP 7 and confirm it appears within two acquisition cycles in a graphics I/O field.
5. Trigger a configured alarm (e.g., set a bit in the alarm-triggering DB) and confirm WinCC generates the alarm with the correct timestamp and acknowledgment state.
6. If the project uses Tag Logging, verify archive segments write to the configured path and that User Archives round-trip read/write correctly.

10. Troubleshooting Common Migration Issues

11. Long-Term Roadmap Beyond V7.5 SP1

Once the migration to V7.x is complete, evaluate whether to plan a second migration to the TIA Portal environment (WinCC Professional / WinCC Unified in STEP 7 / TIA Portal). The TIA path provides a single engineering toolchain for S7-400 (via WinCC Professional with S7-400 HMI connectivity) and a modern UI framework, but it does not natively support a S7-400 CPU as the controller for new HMI tags in the same way STEP 7 V5.5 does. For brownfield sites, the practical target is often WinCC V7.5 SP1 + STEP 7 V5.6 on Windows 10 LTSC, leaving the TIA migration as a separate, larger project. This staged approach lets you preserve the V6.0 SP4 investment while modernizing the platform and OS.

12. Frequently Asked Questions