Why 'Maintenance Station Standard' Option Is Grayed Out in SIMATIC PCS 7 V8.1

In SIMATIC PCS 7 V8.1, the 'Maintenance Station Standard' configuration option is disabled or grayed out when the Engineering Station lacks a valid Maintenance Station Engineering license (such as 6ES7658-5AX18-0YA5), when Automation License Manager (ALM) has not refreshed active keys after installation, or when the target OS station type in the Plant Hierarchy is incorrectly set to an OS Client rather than an OS Single Station or OS Server. To resolve this, install the required MS Engineering license, verify key availability via 'Check' in ALM, restart SIMATIC Manager, and configure the target PC station as a dedicated Maintenance Station.

Root Causes of Disabled Maintenance Station Standard Option

In SIMATIC PCS 7, the Maintenance Station (MS) provides plant-wide asset management, intelligent diagnostics, and predictive maintenance for field devices, network components, and automation controllers.

When attempting to assign the Maintenance Station role under Options -> Plant Hierarchy -> Define Maintenance Station, engineers frequently find that the radio button for Maintenance Station Standard is disabled or grayed out, permitting only Maintenance Station Basic or none at all.

This behavior is governed by strict system preconditions and license enforcement:
1. Missing MS Engineering License on ES: While the runtime target requires an MS Runtime license, the Engineering Station (ES) itself requires a dedicated Maintenance Station Engineering license (SIMATIC PCS 7 Maintenance Station Engineering). Without this engineering license present in Automation License Manager (ALM), SIMATIC Manager disables the configuration of Standard Maintenance Stations.
2. Unrefreshed License Service Cache: If the license key was transferred into ALM while SIMATIC Manager was running, the internal license daemon may not have updated its runtime cache.
3. Target PC Station Type Mismatch: A Maintenance Station Standard requires a dedicated standalone PC Station configured as an OS Single Station or OS Server (MS Server). If the selected station in the project tree is an OS Client or standard application node, the option remains grayed out.
4. Insufficient AS/OS Process Objects (PO): If the multiproject has exhausted its available diagnostic asset POs, advanced maintenance features become restricted.

Maintenance Station Licensing Architecture - Basic vs Standard

Siemens differentiates plant asset management into two distinct implementation models:

Maintenance Station Basic (Integrated)

Included with standard PCS 7 OS runtime licenses.
Operates directly on the existing Operator Station (OS Server or OS Single Station).
Provides basic diagnostic screens for automation system hardware (CPUs, CPs, ET 200 racks).
Does not support extensive SIMATIC PDM field device parameterization or advanced cyclic diagnostic asset archiving.

Maintenance Station Standard (Standalone)

Designed as an autonomous, plant-wide asset management system.
Deployed on a dedicated PC Station (MS Server and optional MS Clients).
Integrates seamlessly with SIMATIC PDM to poll HART, PROFIBUS PA, and FF field instruments for NAMUR NE107 diagnostic statuses.
Requires dedicated licensing:
Engineering License: SIMATIC PCS 7 Maintenance Station Engineering V8.1 (MLFB 6ES7658-5AX18-0YA5).
Runtime License: SIMATIC PCS 7 Maintenance Station Runtime V8.1 (e.g., base package 6ES7652-5AX18-0YA0 plus scalable Asset Tag packs).

[!IMPORTANT]
Distinguish software engineering licenses, runtime capacity licenses, and optional PDM device packs. Always validate final license quantities and order numbers (MLFBs) against current Siemens catalogs and obtain an authorized distributor quotation prior to procurement.

Comparison Table - Maintenance Station Basic vs Standard

The following table contrasts the functional capabilities, engineering prerequisites, and licensing structures of Maintenance Station Basic and Standard.

Architecture / FeatureMaintenance Station BasicMaintenance Station StandardHost System DeploymentCo-located on existing WinCC OS ServerDedicated standalone MS Server / Single StationEngineering LicenseIncluded with standard PCS 7 Engineering6ES7658-5AX18-0YA5 (MS Engineering License)Runtime LicenseStandard OS Runtime POs6ES7652-5AX18-0YA0 + MS Asset PackagesSIMATIC PDM IntegrationLimited diagnostic calloutFull integration with cyclic background device pollingNAMUR NE107 DiagnosticsController and rack level onlyFull field device integration (Failure, Check, Maintenance)Target Station in HW ConfigExisting OS Server WinCC ApplicationDedicated WinCC Application / WinCC Single StationDiagnostic Screen GenerationGenerated within standard OS graphicsDedicated plant hierarchy diagnostic structure

Step-by-Step Configuration and License Refresh Procedure

To resolve the grayed-out option and successfully enable Maintenance Station Standard, execute the following engineering steps:

Verify and Refresh Licensing in ALM:
* Close SIMATIC Manager and all engineering tools.
* Open Automation License Manager (ALM).
* Verify that the license PCS 7 Maintenance Station Engineering is installed on the local hard drive.
* Select the license key, right-click, and select Check. Confirm status shows valid without errors.
Verify Multiproject License Accounting:
* Open SIMATIC Manager.
* In the project tree, right-click the Multiproject root folder and select PCS 7 License Information.
* Under the Engineering Licenses tab, confirm that Maintenance Station Engineering shows a count of 1 (Available) and 0 (Missing).
Configure Dedicated PC Station in SIMATIC Manager:
* Insert a new PC Station in the Component View and name it (e.g., MS_Server).
* Open HW Config for this PC Station.
* Insert a WinCC Application (for a dedicated MS Server) or WinCC Application (standalone) (for MS Single Station) in Slot 1.
* Insert the appropriate network communications processor (e.g., CP 1623 or IE General) in the virtual rack.
* Save and compile the hardware configuration.
Define Maintenance Station in Plant Hierarchy:
* Switch to the Plant View in SIMATIC Manager.
* Select the top-level Plant Hierarchy folder.
* Click Options -> Plant Hierarchy -> Define Maintenance Station.
* The Maintenance Station Standard radio button is now active and selectable.
* Select Standard, browse to the configured MS_Server WinCC Application, and assign the diagnostic area hierarchy folder.
* Click OK to confirm.
Generate Diagnostic Screens:
* In Plant View, select the root folder and click Options -> Plant Hierarchy -> Create/Update Diagnostics Screens.
* Confirm driver generation and compilation.

Verification

Confirm successful configuration and operational readiness using the following procedure:

Check Plant Hierarchy Icons:
* In SIMATIC Manager Plant View, verify that the dedicated diagnostic hierarchy folder displays the specialized Maintenance Station wrench icon.
Verify OS Compilation for MS:
* Right-click the MS OS project and select Compile OS.
* Ensure that the diagnostic screens and asset tags compile with zero errors.
Launch MS Runtime Diagnostics:
* Activate WinCC Runtime on the Maintenance Station.
* Navigate to the Overview screen. Confirm that the top navigation bar displays the Maintenance Station overview button and diagnostic hierarchy tree without license violation warnings.

Limitations and Operational Precautions

Prohibition on Standard Operator Clients: An MS Client must be explicitly configured as an MS Client or configured to load MS server data; standard OS operator clients cannot display detailed PDM maintenance views without proper PDM client options.
Asset Tag Consumption: Every monitored intelligent field instrument, drive, and remote I/O head consumes an MS Asset Tag. Monitor asset license consumption via ALM to prevent runtime license overruns.
Simultaneous PDM Access: Background cyclic polling by the Maintenance Station must be scheduled to avoid conflicting with manual device calibration sessions initiated by instrumentation technicians.

Engineer FAQ

Can I install Maintenance Station Standard on the same physical server as an OS Server?

While technically possible in small skid setups, Siemens strongly advises against hosting MS Standard on a primary WinCC OS Server in production plants. The background diagnostic polling and SQL archive load can degrade real-time operator screen update performance.

Does Maintenance Station Basic require SIMATIC PDM?

No. MS Basic monitors automation hardware (racks, power supplies, CPUs, CPs) using internal PCS 7 diagnostic blocks (MOD_D1, RACK) without requiring SIMATIC PDM.

Why does the license check fail even though ALM shows the key is present?

SIMATIC Manager queries the license service upon startup. If a license is added while SIMATIC Manager is running, restart SIMATIC Manager. Also verify that the license version matches your PCS 7 release (e.g., a V8.0 MS license cannot authorize V8.1 engineering).