Recovering Lost Process Object Licenses When the Original PCS 7 Project is Missing or Deleted

In SIMATIC PCS 7, when an engineer loses the original project used to download to an Automation Station and needs to reallocate Process Objects (POs), the recovery procedure depends on the controller hardware. If using modern CPU 410-5H controllers, AS Runtime Process Objects are hardware-licensed directly on the System Expansion Card (SEC) plugged into the CPU, meaning PO capacity remains intact on the controller hardware and does not require booking back into the Engineering Station database. However, for classic S7-400 systems (where software PO licenses are tracked via project GUIDs on the ES), losing the offline project leaves booked licenses trapped in the ES database. To recover classic software POs, you must restore the original project from a backup, execute 'Transfer back Process Objects' in License Information, or contact Siemens Technical Support with proof of purchase to reset the license pool.

Executive Summary

Process Object (PO) licensing governs controller runtime capacity and WinCC tag scaling across SIMATIC PCS 7 plants. In field environments, unexpected Engineering Station failures, lost USB archives, or accidental project deletions can leave engineers in a dilemma: an operating controller holds licensed logic, but the engineering environment cannot 'book back' Process Objects because the original project database is missing. Control engineers often fear that controller licenses are permanently lost. Understanding the fundamental architectural divide between CPU 410-5H hardware System Expansion Cards (SEC) and classic S7-400 software-booked licensing pools prevents costly and unnecessary license repurchasing.

Architecture and Fundamental Mechanics

The tracking and authorization mechanics of PCS 7 Process Objects operate through distinct hardware and software architectures:

The Modern CPU 410-5H System Expansion Card (SEC) Architecture:
* On CPU 410-5H controllers, AS Runtime Process Objects are not debited from a software pool on the Engineering Station.
* The PO license capacity (e.g., 500 PO, 1,000 PO, or 2,000 PO) is physically encoded in the microchip of the System Expansion Card (SEC) inserted directly into the CPU.
* When an engineer creates a new project and downloads charts to a CPU 410-5H, the CPU firmware autonomously counts the technological blocks in the incoming program and compares the count to its internal SEC capacity.
* Because the license resides on the physical hardware SEC, losing the offline project on the ES has zero impact on the controller's PO capacity. A new or reconstructed project can be downloaded directly without booking back POs.
The Classic S7-400 Software PO Booking Architecture:
* On classic S7-400 controllers (e.g., CPU 417-4, CPU 416-3), AS RT PO licenses reside in Automation License Manager (ALM) on the ES.
* During compilation and download, SIMATIC Manager tracks PO debits inside the project database (.s7p) and tags them with internal project GUIDs.
* If a user deletes the project directory in Windows without executing 'Transfer back Process Objects', the ES database retains the booked debit, locking those licenses and showing them as consumed.
* Creating a brand-new project generates a new project GUID; SIMATIC Manager will not allow 'booking back' licenses that were assigned to a different project GUID.

Step-by-Step Implementation Procedure

Follow these procedures to resolve PO licensing issues depending on your controller platform:

Determine Controller Platform (CPU 410-5H vs. Classic S7-400):
* Inspect the physical CPU or HW Config station.
* If CPU 410-5H: Proceed to Step 2.
* If Classic S7-400 (CPU 414 / 416 / 417): Proceed to Step 3.
Procedure for CPU 410-5H (Hardware SEC - No Booking Back Required):
* In your new or reconstructed project, build the required CFC charts.
* Open HW Config and compile.
* In CFC, compile the charts and initiate download (PLC > Download).
* The CPU 410-5H firmware reads the SEC capacity directly from hardware.
* If the configured blocks do not exceed the SEC limit (e.g., 850 blocks against a 1,000 PO SEC), the download succeeds immediately without any 'book back' requirement.
* Check Module Information > Performance to verify available SEC capacity.
Procedure for Classic S7-400 (Software PO Recovery):
* Attempt Project Retrieval from Backup: Check network shares, tape backups, or decommissioned ES hard drives for a .zip archive of the original multiproject. If found, retrieve the project (File > Retrieve) in SIMATIC Manager.
* Execute Transfer Back: In the retrieved project, right-click the root folder, select PCS 7 License Information, locate the target AS, and click Transfer back Process Objects to credit the licenses back to the ES pool.
Handling Irretrievably Lost Projects on Classic S7-400:
* If the project archive is permanently lost and the ES license pool is depleted:
* Collect your official License Certificate of License (CoL) documents and ALM license serial numbers.
* Submit an official Technical Support Request to Siemens Industry Online Support (SIOS).
* Explain that a physical ES drive crash resulted in unreturned software PO bookings.
* Siemens Customer Support can provide an authorization reset utility or replacement license authorization upon verification.

Verification

For CPU 410-5H, open SIMATIC Manager, select the controller, and choose PLC > Module Information > Performance. Verify that 'Maximum Process Objects' and 'Current Process Objects' report valid numbers and that the CPU operates in RUN without license error LEDs. For classic S7-400, open PCS 7 License Information on the ES; verify that 'Currently available' displays a positive balance of spare POs.

Limitations and Operational Precautions

Never attempt to edit raw ALM .ekb license files using third-party hexadecimal tools; doing so corrupts digital cryptographic signatures and permanently destroys license keys. Always maintain automated off-site PKZip archives of the complete PCS 7 multiproject.

Engineer FAQ

Do I need to book back POs when downloading to a CPU 410-5H?

No. On CPU 410-5H, Process Objects are licensed on the physical System Expansion Card (SEC) in the CPU, eliminating software booking dependencies on the ES.

Why does SIMATIC Manager warn about lost POs when deleting a project?

For classic S7-400 systems, deleting a project without transferring back POs strands the booked software licenses in the ES database.

Can I upload the project from the CPU to recover the original project?

While raw blocks can be uploaded, CFC graphical charts and Plant Hierarchy cannot be reverse-engineered from CPU work memory without specialized XML chart archives.