AS PO Configured vs Booked vs Loaded in Siemens PCS 7 CPU410

The terms configured, booked, and loaded to CPU refer to three distinct lifecycle states of Automation Station Process Objects (AS PO) inside a Siemens PCS 7 multiproject. On the CPU410-5H (and the wider CPU 410-5H EEC family), these counters drive the runtime license accounting that determines whether the plant can start, whether alarm-archive blocks will compile, and whether operator-and-monitoring (O&M) objects will be created on the Engineering Station (ES). Mis-reading these counters is one of the most common causes of failed downloads, license shortfall errors during CFC compile, and unexpected runtime restrictions after a CPU swap.

This reference explains what each value represents, how the counters interact with the CPU410 expansion-card license container, and how to recover licenses when the project has been downloaded to a test CPU without being booked back.

1. What Is an AS Process Object?

An AS PO is a runtime-relevable object generated by a CFC chart that carries the s7_m_c attribute, meaning that PCS 7 must publish it to the OS faceplates, alarm logs, trend archives, and operator input lists. Anything in the CFC/SFC editor that derives from a process object block library (APL — Advanced Process Library, or the older PCS 7 V8 libraries) counts as one AS PO, multiplied by the number of instances the chart contains.

Typical instances that produce AS PO entries:

• Valve, motor, damper, PID controller faceplates (e.g. CTRL_PID, VLV, MOT from the APL).
• Digital and analog operator input blocks (OP_D, OP_A, OP_I).
• Message-capable blocks of every type, including MSG_LOCK, MSG_ACK, alarm and event blocks.
• Sequential function charts (SFC) that drive OS-visible steps, transitions, and prompts.
• WinCC-tag generating blocks compiled for the runtime faceplate hierarchy.

Each faceplate-related alarm class, each message-relevant block instance, and each SFC step counts as a separate object. A single MOT block in CFC with the s7_m_c attribute ticked produces 1 AS PO; an INTERLOCK block with eight digital inputs counts as 1 PO only because the PO is the controller-level instance, not the individual I/O points it reads.

For block-level details, see the PCS 7 Process Object Structures manual (Siemens Support entry ID 109747216).

2. CPU410-5H Licensing Architecture

The CPU410-5H (order numbers 6ES7410-5HX08-0AB0 for the standard variant and 6ES7410-5HM08-0AB0 for the EEC fail-safe variant) does not enforce a hard PO ceiling in firmware the way that CPU 416 or CPU 417 do. Instead, the license is held on a removable SIMATIC Memory Card (System Card SD) that sits behind the front cover alongside the optional expansion card slot. License PO are booked into the CPU410 container through the ES function "Download to Target System > PC Station" or "Download to Target System > AS", and are stored in the System Card's KEY.LIC-style license area.

For order numbers and firmware variants refer to the CPU 410-5H Equipment Manual.

3. The Three Counters — Configured, Booked, Loaded to CPU

The PCS 7 ES dialog SIMATIC Manager > Options > PCS 7 > AS Process Object Counter (or the equivalent inside the TIA-PCS 7 bridge in PCS 7 V9.1 onward) shows four values:

3.1 Configured

The "Configured" value is the result of an offline analysis of the entire multiproject. PCS 7 walks every CFC in every AS subproject, evaluates the s7_m_c attribute on each block instance, and sums them. The configured total in a project named UTCL_PATNA of 2 773 therefore equals the cumulative AS PO across all AS sub-projects, regardless of which CPU they are targeting. It does not change when you download.

3.2 Booked

Each download against a specific AS sub-project transfers PO booking from the ES license database to the System Card of that CPU410. The "Booked" value is therefore a per-multiproject tally of PO that the ES believes have already been credited to physical hardware. Once a PO has been booked to a System Card, it cannot be re-booked to another CPU without an explicit Book Back action.

3.3 Loaded to CPU

This counter is read live from the currently online CPU410 (read-only). It reports the number of s7_m_c instances in the S7 program image of that one CPU at the moment of the query. If the offline configuration of the AS sub-project exceeds the number of PO actually compiled into the S7 program (for example because not all CFCs have yet been compiled), "Loaded to CPU" can be lower than "Configured" for that AS, even when no download has occurred.

4. Why Booked and Loaded to CPU Differ

In a healthy system, Booked = Loaded to CPU. They diverge when:

1. A second CPU was used as a temporary download target (test bench, FAT rig, or replacement CPU).
2. The project was downloaded to a CPU that has since been formatted or whose System Card was re-imaged.
3. PO were booked to a CPU and then the S7 program was partially deleted (CFC charts removed) without performing a book-back.
4. The license expansion card was removed or swapped without first booking back the PO that referenced it.

5. Multiproject Aggregation

In the PCS 7 dialog the four columns are aggregated at the multiproject level. The configured number therefore aggregates every AS in the multiproject (e.g. 2 773 PO across all AS subprojects), while Booked and Loaded to CPU refer specifically to the CPU currently online on the ES. The Limit column belongs to that single CPU410.

This aggregation is important when verifying a fresh project: a low "Loaded to CPU" value combined with a high "Configured" value is normal, because only one AS at a time can be online to the ES for the diagnostic query. The check that matters is:

• Configured ≤ Limit for each individual AS sub-project before any download.
• Booked ≥ Loaded to CPU for the online CPU after the download completes.

6. PO Counting Rules by Block Category

For the canonical reference list, consult the PCS 7 Process Object Structures manual and the APL block help inside SIMATIC Manager.

7. License Container and Expansion Card Mechanics

The CPU410 stores two license sets: one on the System Card (always present, fixed baseline) and one on the optional PO expansion card (a Siemens SIMATIC plug-in card). License PO are upgraded by ordering part numbers such as:

The ES-side license database holds the master record and pushes the credit to the System Card on download. The expansion card is read by the CPU410 firmware at startup. If the expansion card is removed while the CPU is online and PO references to it exist, the CPU will start in degraded mode and signal the diagnostic "License missing".

8. Insufficient-Licensing Diagnostic Procedure

1. Open SIMATIC Manager > Options > PCS 7 > AS Process Object Counter.
2. Read the four columns for the multiproject. Note the AS subproject currently online.
3. Compare Loaded to CPU against Booked. If Loaded to CPU > Booked, identify whether the active CPU differs from the one targeted by the AS subproject.
4. Open PLC > Online > Accessible Nodes, confirm the CPU's article number (e.g. 6ES7410-5HX08-0AB0) and serial number. Match it to the System Card license database entry.
5. If the CPU was swapped, perform a Book Back against the original CPU image by selecting the old AS sub-project and invoking Options > PCS 7 > PO Management > Book Back on the previous System Card image. The license pool is freed.
6. If a missing or physically removed expansion card is the cause, re-seat the expansion card and re-trigger the PO download, or purchase the additional license.
7. Re-run the AS Process Object Counter to confirm the four columns reach steady state.

9. Book Back Procedure (CPU Migration / Replacement)

When a CPU410 needs to be replaced (failure, hardware upgrade, FAT return) the PO booked to its System Card must be returned to the ES license pool before they can be re-booked to the new hardware.

1. Insert the old System Card into a USB SD-card reader on the ES.
2. In SIMATIC Manager select Options > PCS 7 > License Management > Book Back PO.
3. Choose the offline image of the old AS; PCS 7 will read the PO counter from the System Card and release the matching credit.
4. Insert the new System Card; perform a fresh Download to Target System on the same AS to re-book the PO against the new CPU.

10. CPU410 vs CPU416 / CPU417 Differences

The presence of the "Loaded to CPU" and "Limit" indicators in the dialog is therefore the visual fingerprint of a CPU410-class controller. The CPU416 / CPU417 AS Process Object dialog reports only Configured and Used.

11. Verification Checklist Before First Commissioning

1. Compile every CFC/SFC in the multiproject.
2. Run AS Process Object Counter at the multiproject level. Sum each AS sub-project's PO.
3. Confirm Configured ≤ Limit for each individual AS, allowing 10–20 % headroom for late project additions.
4. Connect to the target CPU410. Read Loaded to CPU and Booked; both should equal the configured PO for that AS.
5. Open WinCC Explorer and confirm the OS-server tag count matches the OS-side PO total (the OS reports the same objects under "Tag Connections" but split into picture-tree PO).
6. Trigger an alarm test and verify the OS alarm log shows the expected message class hierarchy.

12. Troubleshooting Matrix

13. Field-Proven Caveats

• PO booking is sticky to the System Card's serial number, not the CPU's serial number. Swapping a CPU410 but keeping the System Card preserves the licenses.
• SFC steps that drive OS prompts count as PO; internal-only steps with no OS attachment do not. Check the S7_m_c attribute on the SFC instance.
• F-runtime (fail-safe) blocks do not consume AS PO. Do not double-count them when estimating ceiling usage.
• PO from third-party libraries (vendor-specific CFCs) follow the same rule: only blocks with the s7_m_c attribute ticked count.
• Bulk-deleting CFC charts without a download leaves the booked PO orphaned. Always trigger a follow-up download to book them back.

14. References and Standards

Refer to the CPU 410-5H Equipment Manual and the PCS 7 Process Object Structures for the canonical definitions. Licensing policy is governed by the PCS 7 installation documentation, in particular the chapter "Process Objects — Configuration and Licensing", which is mirrored in the PCS 7 Help under Licensing > Process Objects.