Can a PCS 7 V9.1 Project Be Retrieved in PCS 7 V9.0?
Do not treat a PCS 7 V9.1 project using APL V9.1 as a supported V9.0 project without a documented reverse-migration procedure. Siemens' V9.1 Readme describes selected upgrades from earlier PCS 7 versions to V9.1, not the reverse direction. Preserve the V9.1 project unchanged and confirm exact versions and a supported route before testing on a separate copy.
Table of Contents
- Version direction
- What Siemens documents
- Safer approach
- Verification
- Limitations and Operational Precautions
- Engineer FAQ
- Technical References
- Related Articles
- Related Tags
Version direction
The question asks whether a project created in PCS 7 V9.1 with APL V9.1 can be retrieved in PCS 7 V9.0; its subject instead says V9.0.3. Confirm the exact target release. The reply cautions against a lower-version open but reports no test result.
What Siemens documents
The PCS 7 V9.1 Readme describes upgrading projects from selected older releases, including PCS 7 V8.2 SP1 and V9.0 SP3. It does not document the reverse direction from V9.1/APL V9.1 to V9.0. Do not infer reverse support or impossibility from a forward upgrade procedure.
Safer approach
Keep the V9.1 archive unchanged. If V9.0 use is required, use a project maintained for that target release or obtain written Siemens guidance for the exact source/target versions and project contents. Test only on a copy with a representative environment.
Verification
Check exact PCS 7 and APL service packs/updates and options. On the separate test copy, verify opening/conversion, library and block compatibility, AS/OS compilation and representative runtime behavior. Opening successfully does not prove compile or runtime compatibility.
Limitations and Operational Precautions
No official reverse-migration procedure or test result was found. The V9.0/V9.0.3 discrepancy and absent project details prevent a precise compatibility conclusion. Preserve the V9.1 source and do not download an older-version project to a plant based only on the forum reply.
Engineer FAQ
Does the V9.1 Readme establish migration back to V9.0? No; it describes selected older-to-V9.1 upgrades.
Does the forum reply prove every reverse open produces errors? No; it is an untested warning, not a result for every project.
Technical References
- PCS 7 Readme V9.1, “Updating PCS 7 projects,” p. 28; opened and read. The documented direction is older selected releases to V9.1, not reverse migration.
- PCS 7 documentation — version-specific migration manuals; no V9.1-to-V9.0 procedure was established.