Diagnosing Lost AS RT Process Objects and Restoring Booked Licenses in PCS 7

When Automation License Manager (ALM) displays a significant deficit in available AS RT Process Objects (e.g., total license of 6000 POs, but only 29 available while the current project books 3344), the missing licenses were booked to other automation stations—such as test bench CPUs, decommissioned controllers, or replaced hardware—without executing the 'Book Back Process Objects' procedure. In SIMATIC PCS 7, downloading to an AS controller transfers PO licenses from the Engineering Station's ALM license key into the CPU's memory. To recover them, connect the ES to the original CPUs and execute 'Book Back'; if hardware was lost or destroyed, contact Siemens Authorization Hotline for license restoration.

Executive Summary

A frequent commercial and engineering crisis in large-scale SIMATIC PCS 7 facilities occurs when an Engineering Station unexpectedly reports a shortage of AS Runtime Process Object (AS RT PO) licenses during compilation or download, despite having purchased thousands of POs. Automation License Manager (ALM) shows thousands of POs as 'booked', yet the active multiproject only accounts for a fraction of that quantity. This article explains the technical mechanics of AS RT PO booking into CPU memory, why downloading twice does NOT consume double POs, and how to safely audit, book back, or restore missing licenses.

Architecture and Fundamental Mechanics

AS RT Process Object Booking and Counting Architecture:

How AS RT PO Licensing Operates in PCS 7:
An AS RT Process Object (PO) license covers technological blocks with operator control and monitoring attributes (S7_m_c := 'true'), such as motors, valves, and closed-loop controllers.
The Booking Mechanism: When an engineer downloads an S7 program to a physical S7-400 or CPU 410-5H controller, the PCS 7 download manager calculates the required PO count and deducts (books) that exact quantity from the master AS RT PO license key stored in ALM, transferring the allocation into the CPU memory.
Downloading Twice Does NOT Consume Double POs:
Downloading repeatedly to the same CPU does not consume additional POs. The CPU maintains its allocated PO credit. Subsequent downloads only book the delta (new blocks added) or return credits if blocks were deleted.
Root Causes of 'Missing' POs in ALM:
1. Download to Test / Staging CPUs: The ES was used to download programs to a temporary staging controller or test bench rack, and the POs were never returned.
2. Replaced / Failed Hardware: A failed CPU was swapped out in the plant; the new CPU required fresh POs, leaving the original POs orphaned inside the dead CPU.
3. Multi-Project Engineering: The ES was used to download multiple independent plant multiprojects sharing the same central ALM pool.
Distinction from Hardware Expansion Cards:
Software AS RT PO licenses in ALM are completely distinct from the physical CPU 410 System Expansion Card (SEC) hardware capacity. Both must be satisfied independently.

Step-by-Step Implementation Procedure

Step-by-Step Procedure to Audit and Book Back Lost AS RT POs:

Audit Active PO Consumption in SIMATIC Manager:
- Open the Multiproject in SIMATIC Manager.
- Select the Multiproject folder -> click Options -> PCS 7 License Information.
- In the 'Process Objects' tab, inspect the table: review 'Booked POs in Project' and 'Actual POs used in AS'.
Identify Orphaned / Booked Controller Allocations:
- In the PCS 7 License Information dialog, check the list of target CPUs.
- Identify any controller names that belong to decommissioned units, test skids, or replaced hardware.
Execute 'Book Back Process Objects' to ALM:
- If the original CPU (or test CPU) is physically accessible over Industrial Ethernet:
- Connect the ES to the CPU network.
- In PCS 7 License Information, select the CPU -> click Book Back Process Objects.
- PCS 7 reads the allocated PO credits from the CPU memory, clears the allocation, and credits the POs back to the master license key in ALM.
Procedure if the Hardware is Lost, Damaged, or Inaccessible:
- If a controller was destroyed or replaced and cannot be booted:
- Open Automation License Manager -> click File -> Generate License Log / Diagnostic Report.
- Export the XML diagnostic file.
- Contact the Siemens Industry Authorization Hotline / Technical Support.
- Submit the diagnostic report and original License Certificate (CoL) with proof of purchase; Siemens will generate a replacement restoration license key to re-credit your ALM license pool.

Verification

To verify PO restoration:
1. Open Automation License Manager (ALM) on the Engineering Station.
2. Locate the 'SIMATIC PCS 7 AS Runtime Process Objects' license key.
3. Verify that the 'Available' column reflects the restored quantity (e.g., matching total license capacity minus currently active project bookings).
4. Perform a test compilation in SIMATIC Manager; verify that zero license shortage warnings are logged.

Limitations and Operational Precautions

Operational precautions:
- Never treat estimated I/O-to-PO ratios as actual license counts; always verify actual license consumption using PCS 7 License Information.
- Do not delete or format an engineering workstation containing master ALM license keys without first transferring licenses to a secure USB transfer stick.
- For redundant AS configurations (S7-400H / CPU 410-5H), the AS RT PO software license is required only once for the redundant pair.

Engineer FAQ

Does downloading a program to the same CPU twice use double the PO licenses?

No. The CPU maintains its allocated PO count. Downloading to the same CPU only books or returns the delta if technological blocks were added or deleted.

How do I return booked POs from a CPU to ALM?

In SIMATIC Manager, go to 'Options -> PCS 7 License Information', select the target controller, and click 'Book Back Process Objects'.

What happens if a CPU fails and I cannot book back the POs?

Contact the Siemens Authorization Hotline with your original Certificate of License (CoL) and an ALM diagnostic export; Siemens can issue a restoration license.

Where do I check how many POs my project currently consumes?

In SIMATIC Manager -> Options -> PCS 7 License Information.

Is AS RT PO licensing the same as CPU 410 SEC capacity?

No. CPU 410 System Expansion Cards (SEC) define hardware controller capacity, whereas AS RT POs in ALM represent software runtime licenses. Both must be adequately sized.