Differentiating CPU 410-5H System Expansion Cards (SEC) and Expansion Packs - Hardware Sizing vs Online Upgrades

In SIMATIC PCS 7, the CPU 410-5H controller decouples physical processing hardware from automation capacity through the System Expansion Card (SEC) and System Expansion Packs. The physical SEC is a hardware card inserted into the CPU 410 that defines the baseline hardware Process Object (PO) limit (such as SEC 100 PO up to SEC 2600+ PO). In a redundant AS 410-5H system, two physical SEC cards are required—one per CPU—with identical PO ratings. System Expansion Packs are software license packages in Automation License Manager (ALM) used to expand an existing SEC's PO capacity online without replacing hardware. Downloading a 100 PO project consumes only 100 AS RT PO software licenses from the ES pool, as the redundant pair is licensed as a single automation station.

Hardware Sizing: The System Expansion Card (SEC) Architecture

The SIMATIC PCS 7 CPU 410-5H Process Automation controller (6ES7410-5HX08-0AB0) features a revolutionary hardware concept. Instead of requiring customers to purchase different CPU models (e.g. CPU 414, 416, 417) based on plant scale, a single high-performance CPU 410-5H covers all tiers. The actual operational capacity is defined by the System Expansion Card (SEC), a micro-memory security token plugged into the CPU front panel:

Hardware System Expansion Card (SEC)Commercial Order Number (MLFB)Hardware Capacity RatingTarget Plant SizeCPU 410-5H SEC 1006ES7653-2CA00-0XB0Up to 100 Process ObjectsSmall package units / skidsCPU 410-5H SEC 5006ES7653-2CB00-0XB0Up to 500 Process ObjectsMedium chemical / utility unitsCPU 410-5H SEC 10006ES7653-2CC00-0XB0Up to 1,000 Process ObjectsStandard plant sectionsCPU 410-5H SEC 16006ES7653-2CD00-0XB0Up to 1,600 Process ObjectsLarge continuous production linesCPU 410-5H SEC 2600+6ES7653-2CE00-0XB0Up to 2,600+ Process ObjectsMaximum capacity DCS operations

Without a valid SEC inserted, the CPU 410-5H will not transition into RUN mode.

Online Upgrades: The Role of System Expansion Packs in ALM

When a facility expands its instrumentation and exceeds its initial SEC PO rating (e.g., growing from 100 POs to 250 POs), it is not necessary to decommission the plant or purchase new physical cards. Siemens provides System Expansion Packs:

System Expansion Packs are commercial upgrade license certificates delivered via Online Software Delivery (OSD) or USB.
Using the Automation License Manager (ALM), an engineer connects the ES to the CPU 410-5H over the Plant Bus.
In ALM, selecting Edit -> Connect target system -> Connect CPU 410 allows transferring expansion tokens directly into the SEC memory.
The expansion occurs online in RUN mode without stopping the controller or interrupting continuous chemical or refining processes.

Redundant Pair Licensing and Process Object Booking Rules

For high-availability redundant systems (AS 410-5H Redundant Pair), engineers must observe two distinct accounting layers:

Hardware Capacity Layer (SEC Cards): A redundant pair consists of two physical CPUs. Therefore, two physical SEC cards are mandatory—one inserted into CPU A and one inserted into CPU B. Both SECs must have the identical PO rating (e.g., two SEC 500 cards). Hardware capacities never pool or sum across redundant CPUs because if one CPU fails, the surviving partner must execute 100% of the automation logic independently.
Software Licensing Layer (Engineering Station ALM Pool): On the Engineering Station, AS RT PO licenses authorize software compilation. In SIMATIC Manager, a redundant pair is configured as a single automation station (SIMATIC 400(1)). Therefore, downloading a project requiring 100 POs deducts only 100 AS RT POs from the ES license pool, not 200 POs.

Verification

Verify SEC hardware rating and software PO booking through these diagnostic checks:

CPU SEC Rating Online: In SIMATIC Manager, select the CPU 410-5H object. Select PLC -> Module Information. Switch to the Memory tab. Verify that System Expansion Card displays the total authorized PO limit (e.g., 500 PO).
Multiproject PO Consumption: In SIMATIC Manager Component View, right-click the Charts folder and select Object Properties. Under the PCS 7 Process Objects tab, confirm the exact number of consumed AS RT POs.
ALM Pool Audit: Open Automation License Manager on the ES. Verify that SIMATIC PCS 7 AS RT PO floating licenses reflect the single-station deduction with sufficient remaining balance.

Limitations and Operational Precautions

When planning and procuring CPU 410-5H hardware and expansion packs, adhere to these mandatory guardrails:

Commercial Accuracy Notice: CPU 410-5H System Expansion Cards and Expansion Packs (6ES7653-2Cx00-0XB0 / 6ES7653-2Cx00-0XE0) are subject to Siemens commercial licensing terms and strict functional rules. Never attempt to mix mismatched SEC capacities in a redundant pair, as doing so prevents redundant synchronization (REDF fault). Always validate final PO counts and part numbers against current Siemens catalogs and authorized distributor quotations.
Do Not Remove SEC in RUN: While expansion packs can be loaded online via ALM, physically ejecting the SEC card from the CPU 410 front panel while in RUN causes an instantaneous CPU hardware trip into STOP mode.
Separate OS RT PO Accounting: AS RT PO capacity on the SEC governs only controller execution. Visualization on WinCC OS Servers requires distinct OS RT PO licenses managed separately.

Engineer FAQ

If I have a redundant CPU 410 with 250 POs, what SECs do I order?

You must order two physical SEC 500 cards (6ES7653-2CB00-0XB0)—one for each physical CPU module—since 250 POs exceeds the 100 PO tier.

Can I transfer an SEC card to a spare CPU 410 if the hardware fails?

Yes. If a CPU 410-5H processor suffers an internal hardware fault, technicians can unplug the SEC card and insert it into a spare CPU 410-5H module, transferring all PO capacity and MAC credentials immediately.

Where is the actual AS RT PO software license stored?

The software license resides in the Automation License Manager on the Engineering Station hard drive. The SEC holds the controller's hardware execution token.