Calculating AS RT PO and OS RT PO Licenses for Redundant CPU 410E Systems in PCS 7

Calculating Process Object (PO) licensing for a SIMATIC PCS 7 V9.0 redundant automation system utilizing CPU 410E controllers requires distinguishing between controller hardware capacity (System Expansion Card), engineering download licenses (AS RT PO), and supervisory operator station licenses (OS RT PO). The CPU 410E (6ES7410-5HM08-0AB0) has an absolute hardware capacity limit capped at 200 POs, with 100 POs pre-licensed on its System Expansion Card (SEC). In a redundant CPU 410E pair, each physical CPU requires an identical SEC card (2x 100 POs). However, engineering AS RT POs are booked once per automation project, while redundant OS Servers require separate identical OS RT PO packages on each physical server.

Process Object Definition in Modern PCS 7

In SIMATIC PCS 7 (since version V7.1 and continuing through V9.x), system licensing is structured around Process Objects (PO) rather than raw tag counts. Engineers migrating from legacy SCADA or classic STEP 7 systems frequently make the mistake of attempting to calculate licenses by counting variables (e.g., assuming 1 PO = 30 tags or 90 tags).

In PCS 7, a Process Object is strictly defined as:
1. Any block instance in a Continuous Function Chart (CFC) that has the Operator Communication and Monitoring attribute (S7_m_c := 'true') AND generates alarm messages via Alarm_8P (e.g., motor blocks MotL, valve blocks VlvL, analog monitoring MonAnL, PID controllers PIDConL).
2. Any Sequential Function Chart (SFC) chart or SFC type instance.
3. System driver blocks (blocks generated in @ charts, such as Pcs7DiIn, Pcs7AnIn, MOD_DHA8) do NOT consume Process Objects.
4. Custom calculation blocks that expose tags to WinCC without generating alarms do NOT consume Process Objects.

Hardware Capacity: System Expansion Card (SEC) for CPU 410E

The SIMATIC S7-410 controller family utilizes a unique hardware scaling architecture. The physical CPU 410 hardware contains top-tier processing power, but its usable capacity is unlocked by the System Expansion Card (SEC) plugged into the CPU:

CPU 410-5H Process Automation (6ES7410-5HX08-0AB0): High-end controller scalable from 100 up to 2,600+ POs.
CPU 410E Entry (6ES7410-5HM08-0AB0): Cost-optimized controller specifically capped at a maximum of 200 POs. It comes pre-equipped with an SEC for 100 POs. It can be expanded by a maximum of 100 additional POs using an SEC expansion package, but cannot exceed 200 POs.

In a redundant system (AS 410E Redundant Pair):
* Because redundancy consists of two physical CPUs executing in lockstep, each physical CPU must have an identical SEC card installed.
* If a redundant station requires 100 PO capacity, you must possess two CPU 410E controllers, each with its included 100 PO SEC card. If expanding to 200 POs, you must order two 100 PO SEC expansion packages (one for CPU A, one for CPU B).

AS RT PO vs OS RT PO Licensing in Redundant Topologies

Engineers must separate AS controller capacity from WinCC OS operator station runtime licensing:

License CategoryInstallation TargetRedundant Sizing RuleOrdering Quantity Example (for 100 PO System)CPU 410E SEC (Hardware)Physical CPU Micro Memory Card SlotEach physical CPU requires identical SEC card2x SEC cards (included with 2x 6ES7410-5HM08-0AB0)AS RT PO (Engineering)Engineering Station (ALM)Booked once per Multiproject download1x AS RT PO package (100 POs on ES)OS RT PO (WinCC Server)OS Server Local Drive (ALM)Each physical OS Server requires identical full PO license2x OS RT PO packages (100 POs for Server A, 100 POs for Server B)OS Redundancy OptionOS Server Local Drive (ALM)1 package covers the redundant pair1x WinCC Redundancy package

When downloading from the Engineering Station:
* The ES checks if sufficient AS RT PO licenses are installed in Automation License Manager. If 50 POs are configured, 50 AS RT POs are booked against the CPU. You do not double the AS RT PO count for redundancy; 50 configured POs consume 50 AS RT POs.
* For the OS Servers, WinCC is licensed per machine. If 100 POs are monitored, OS Server A requires an OS RT PO 100 license, and OS Server B requires an OS RT PO 100 license. You must order two OS RT PO license packages.

Ordering Rules and Complete 16-Character MLFBs

To ensure procurement accuracy, reference verified 16-character Siemens order numbers:

[!IMPORTANT]
Commercial Accuracy Guardrail: Software licensing rules, package contents, and pricing vary by region and contract status. Software packages, order numbers, and capacity limits must be verified against current Siemens Industry Mall catalogs and validated through an authorized Siemens distributor quotation prior to procurement.

Representative Siemens order numbers include:
* SIMATIC PCS 7 CPU 410E Process Automation Controller (with 100 PO SEC): 6ES7410-5HM08-0AB0
* SIMATIC PCS 7 CPU 410 SEC Expansion 100 PO (Hardware capacity): 6ES7653-2GA00-0XB0
* SIMATIC PCS 7 Software Runtime License AS (PO 100): 6ES7653-2BA00-0XB5
* SIMATIC PCS 7 Software Runtime License OS (PO 100): 6ES7658-2XA00-0XB0
* SIMATIC PCS 7 OS Single Station / Server Package V9.0: 6ES7658-2BA58-0YA0

Verification

To verify process object licensing and usage:
1. In SIMATIC Manager, select the top-level Multiproject folder.
2. Right-click and select PCS 7 License Information....
3. Inspect the table: review Configured Process Objects (AS) and Configured Process Objects (OS).
4. Open Automation License Manager on the Engineering Station; confirm that the installed count of AS RT PO exceeds the configured count.
5. In ALM on each OS Server, confirm that OS RT PO licenses match or exceed the configured OS PO count.

Limitations and Operational Precautions

Never exceed the 200 PO hardware capacity ceiling on a CPU 410E. If plant expansion requires more than 200 Process Objects, the physical CPU 410E controllers must be replaced with full CPU 410-5H controllers (6ES7410-5HX08-0AB0). Operating with a PO license overrun will trigger recurring unacknowledged licensing pop-up windows on operator screens, potentially obscuring process graphics during operations.

Engineer FAQ

Does using the Advanced Process Library (APL) consume more POs than classic libraries?

No. A standard motor block (MotL) in APL consumes exactly 1 Process Object, which is identical to the classic library motor block (MOTOR). APL does not increase license consumption.

Do I need to buy two AS RT PO packages for a redundant S7-400H or CPU 410 pair?

No. AS RT PO engineering licenses are booked per configured automation program. A redundant CPU pair represents one logical controller program and consumes one set of AS RT POs.

Why must I buy two OS RT PO packages for redundant OS Servers?

Because WinCC Runtime executes independently on both physical server machines to maintain hot-standby redundancy. Each physical server must be legally licensed for the total monitored PO count.