What Happens When a PCS 7 V8.2 CPU 410-5H Exceeds Its Process-Object Limit?

Adding logic offline does not by itself stop a running CPU 410-5H. Before downloading a project that needs more process objects than the System Expansion Card (SEC) capacity, upgrade that capacity; PCS 7 V8.2 supports an online SEC upgrade when PCS 7 and CPU firmware are both V8.1 or later and the SEC is product version 2 or later. Separately, an AS RT PO license shortage produces a confirmation message at download; Siemens says the engineer may cancel or continue, with unavailable licenses recorded as a shortage.

Two different PO limits apply

For a CPU 410-5H, distinguish the maximum PO volume stored on the SEC from the countable AS RT PO engineering/runtime license. The SEC defines the PO capacity to which that CPU can be upgraded. The AS RT PO license is checked by PCS 7 for downloading the AS project; it is not the SEC capacity limit.

In SIMATIC Manager, Options > PCS 7 License Information displays configured AS process objects and licensing information. The CPU's SEC capacity can be inspected separately in the CPU/online hardware information. Do not treat a displayed 1600-PO SEC volume and the available engineering AS RT PO count as one balance.

What happens at download

The PCS 7 V8.2 licensing manual states that when a program contains fewer process objects than the previously downloaded project, the download automatically increases the number of available process-object licenses. If insufficient countable licenses are available, PCS 7 issues a license-violation message requiring confirmation. The engineer can cancel the download or continue; the required but unavailable licenses are recorded as a shortage. Purchased licenses are registered at the next download.

This behavior concerns the countable AS RT PO license. The manual does not say that such a licensing warning itself stops the CPU. If the project exceeds the SEC's PO capacity, increase the CPU 410-5H's SEC volume through the documented online upgrade before trying to load that larger project.

Check the project and installed capacity

In SIMATIC Manager, select the project or multiproject and open Options > PCS 7 License Information. Select Process objects (AS RT PO) to review the project's configured, license-relevant objects and the licensing information.
Inspect the CPU 410-5H's PO volume and firmware through the appropriate online CPU/module information. Confirm the SEC product version; online upgrading requires SEC product version 2 or later.
Compare the configured PO requirement with the SEC's existing capacity. Separately check whether the engineering station has enough countable AS RT PO licenses for the download.
For a redundant AS, plan symmetrical PO-capacity expansion across both CPUs. The expansion packs cannot be split between CPUs or SECs.

Online-upgrade prerequisites and pack sizes

The Siemens CPU 410-5H controller manual for the V8.2 era specifies these prerequisites for increasing SEC PO volume online:
- SIMATIC PCS 7 V8.1 or later.
- CPU 410-5H firmware V8.1 or later.
- CPU configured in HW Config with firmware V8.1 or later.
- SEC product version 2 or later.

CPU 410 Expansion Packs are available in 100-PO and 500-PO sizes. Packs may be combined to reach the needed increase, but each pack must be assigned in full to one CPU/SEC. On a redundant system, the added PO volume must be distributed symmetrically between both CPUs. Thus, increasing a redundant pair from 1600 to 2600 PO per CPU means a 1000-PO capacity increase per CPU (2000 PO total), which can be formed from four 500-PO packs if that combination is appropriate for the installed version and orderable product.

Online SEC upgrade procedure

The V8.2 controller manual describes the upgrade as a four-stage process:
1. Obtain CPU 410 Expansion Packs in the required 100-PO and/or 500-PO sizes. For a redundant AS, calculate a symmetric capacity increase.
2. In Automation License Manager (ALM), connect to the CPU 410-5H automation system and transfer the expansion-pack license key(s) to the target AS. ALM creates a PO activation file.
3. Submit the activation file to Siemens through a Support Request for checking and release. Siemens returns a PO release file.
4. Transfer the release file to the CPU's SEC using ALM. The manual says that for a redundantly configured AS, select only one CPU; PO distribution to both CPUs occurs automatically.

The CPU must be switched on and functional during preparation, but the manual states that preparation does not depend on its operating mode. Follow the exact instructions in the PCS 7 V8.2 Service Support and Diagnostics manual and the installed ALM version; do not assume the licensing preparation is the same as downloading a project.

When 2600 PO is described as unlimited

The V8.2 CPU 410-5H manual describes the capacity as unlimited after reaching 2600 PO on the SEC, meaning projects can use POs until the CPU's physical memory limit is reached. It is not an unlimited physical resource. Siemens also offers a 2K+ PO bundle option; confirm the exact product and compatibility with Siemens for the installed hardware and licensing setup.

Verification

After the online upgrade, confirm in ALM that the SEC's PO capacity reflects the intended increase. Confirm the PCS 7 project's configured PO count independently in PCS 7 License Information. For a redundant AS, verify both CPUs have the intended symmetric capacity and the system is healthy before attempting the larger project download. A successful capacity upgrade does not itself establish that the project is within all CPU memory or engineering constraints.

Limitations and Operational Precautions

These instructions are version-scoped to PCS 7 V8.2 and the CPU 410-5H online-upgrade requirements documented by Siemens. Confirm the CPU's actual firmware, the version configured in HW Config and the SEC product version before proceeding. The ticket identifies CPU order number 6ES7 410-5HX08-0AB0 and firmware V8.1, but does not clearly establish the SEC product version.

Online upgrading changes capacity assigned to the SEC; Siemens warns that PO capacity assigned to a CPU/SEC cannot later be relocated and that packs cannot be subdivided. Plan the redundant allocation before activation. Treat project downloads and CPU operation changes under the site's approved change-control and process-risk procedures. Retain current project backups and coordinate the download decision with operations.

Engineer FAQ

Will creating an additional PO offline stop the running CPU? The documented licensing behavior is checked when downloading. An insufficient countable AS RT PO license causes a confirmation message; PCS 7 permits cancelling or continuing that download and records a shortage. The manual does not state that merely adding logic offline stops a running CPU.

What if the configured project exceeds the SEC PO volume? Increase the CPU 410-5H SEC capacity through the supported online upgrade before loading a project that requires more volume. Do not mistake the AS RT PO license count for SEC capacity.

Are the online-upgrade prerequisites met by PCS 7 V8.2 and CPU firmware V8.1? They meet the PCS 7 and CPU firmware minimums in Siemens' guide, provided the CPU is configured with firmware V8.1 or later in HW Config and the SEC is product version 2 or later.

Do both CPUs in a redundant AS need equal PO capacity? Siemens requires the PO volume to be distributed symmetrically between the two CPUs. In the documented ALM process, select one CPU for the upgrade and the distribution occurs automatically.

Does “unlimited” mean there is no CPU limit? No. The manual uses “unlimited” for reaching 2600 PO capacity on the SEC, then states that use is limited by available physical CPU memory.

Technical References

Siemens, Process automation with the SIMATIC PCS 7 CPU 410-5H controller, V2.2 (11/2016), §2.5, “Online upgrading of CPU 410-5H process objects”: https://cache.industry.siemens.com/dl/files/331/96839331/att_870773/v6/96839331_PCS7_CPU_4105H_V82_en.pdf
Siemens, Licenses and configuration limits (V8.2), §§3.3 and 3.11, PO counting and response to insufficient AS license keys: https://cache.industry.siemens.com/dl/files/967/109485967/att_878560/v1/ps7lic_en-US_en-US.pdf
Siemens, Service Support and Diagnostics (V8.2), §3.5.2, CPU 410 Expansion Pack and redundant SEC upgrade requirements: https://cache.industry.siemens.com/dl/files/965/109485965/att_878553/v1/ps7slf_b_en-US_en-US.pdf

What Happens When a PCS 7 V8.2 CPU 410-5H Exceeds Its Process-Object Limit?