Excluding Individual Field Devices from Diagnostic Screen Generation in PCS 7 Maintenance Station

To deactivate or exclude an individual field device from diagnostic screen generation in SIMATIC PCS 7 Maintenance Station (MS Standard or MS Basic in V8.2 SP1 / V9.0), you have three options depending on your engineering stage: (1) In HW Config, open the device's Object Properties, navigate to the Diagnostics or Options tab, and uncheck 'Diagnostic Interrupt' or 'Report system diagnostics'; (2) In SIMATIC Manager Plant View, relocate the device's diagnostic CFC chart outside the monitored Plant Hierarchy hierarchy folder or deselect 'OCM possible' in block properties; or (3) For runtime suppression without re-engineering, place the device's diagnostic driver block (e.g., Pcs7AnIn or MS_DIAG) into 'Out of Service' mode (OosLi = 1 or via faceplate). Finally, execute 'Create/Update Diagnostic Screens' in Plant View to regenerate the WinCC screens.

Executive Summary

The SIMATIC PCS 7 Maintenance Station (MS) provides comprehensive plant asset management by automatically mapping hardware components—such as S7-400 CPUs, CP communications processors, ET 200 remote I/O racks, field drives, and HART field devices—into standardized WinCC diagnostic screens. However, in operational plants, certain non-critical field instruments, temporary test sensors, or decommissioned auxiliary skids may flood maintenance views with irrelevant maintenance requests or nuisance diagnostic alarms. Engineers frequently need to exclude specific field devices from generating diagnostic block icons and hierarchy nodes without dismantling the underlying automation control logic. By adjusting module interrupt properties in HW Config, modifying Plant Hierarchy assignments, or invoking Out of Service modes, maintenance displays remain focused on critical production assets.

Architecture and Fundamental Mechanics

The Maintenance Station diagnostic generation architecture operates through an automated chain linking hardware definitions to supervisory SCADA graphics:

Hardware Diagnostic Driver Generation: When CFC charts are compiled with 'Generate module drivers' enabled, PCS 7 scans HW Config and instantiates system diagnostic blocks (MOD_D16, MOD_HA, RACK, DPAY_CON, etc.). These blocks monitor hardware health and route status words to the maintenance system.
Plant Hierarchy to Screen Generation: In SIMATIC Manager Plant View, executing Plant Hierarchy -> Create/Update Diagnostic Screens triggers an automated engineering script. This script traverses the Plant Hierarchy, identifies all blocks with active Operator Control and Monitoring (OCM possible) attributes, and constructs the multi-tier diagnostic picture tree (@Diagnostic.pdl, @Maintenance.pdl) on the designated MS Server.
Deactivation Mechanics:
- HW Config Diagnostic Suppression: If diagnostic interrupt reporting is disabled on an I/O module or fieldbus device, the AS operating system suppresses diagnostic telegrams (OB82). Module drivers do not evaluate fault states for that device.
- Plant Hierarchy Filtering: The MS generation compiler only creates diagnostic screen icons for devices residing within hierarchy folders designated for Maintenance Station monitoring. Moving an unmonitored device to a non-monitored folder prevents icon placement on the overview screens.
Runtime 'Out of Service' (OoS): At runtime, putting an asset's channel or diagnostic block into Out of Service (OosAct = 1) changes the Maintenance Station icon badge to a wrench/lock symbol and suppresses all alarm generation, effectively isolating the device from asset management KPI calculations without modifying software.

Step-by-Step Implementation Procedure

Apply one of the following methods to exclude a field device from the Maintenance Station:

Method 1: Hardware Diagnostic Disablement in HW Config

Open SIMATIC Manager and double-click Hardware under the target S7-400 station.
Locate the specific field device (e.g., an analog input module on an ET 200M or ET 200SP rack, or a PROFIBUS PA transmitter).
Double-click the module to open Properties.
Navigate to the Inputs or Diagnostics tab.
Uncheck the checkbox labeled Diagnostic Interrupt or Report System Diagnostics.
Save and compile HW Config, then download changes to the AS.

Method 2: Hierarchy and OCM Deselection in Plant View

Switch to Plant View in SIMATIC Manager.
Open the CFC chart containing the diagnostic driver block or channel block for the device.
Right-click the block (e.g., Pcs7AnIn or MOD_D16) and select Object Properties.
Uncheck the attribute Operator Control and Monitoring (OCM).
Alternatively, move the diagnostic chart into a Plant Hierarchy folder where Diagnostics is not enabled in folder properties.

Method 3: Regenerate Diagnostic Screens

In SIMATIC Manager Plant View, right-click the root Plant Hierarchy folder.
Select Plant Hierarchy -> Create/Update Diagnostic Screens.
In the dialog, verify the target Maintenance Station OS Server and click OK.
The compiler rebuilds the WinCC diagnostic picture tree, omitting the excluded hardware devices.
Perform an OS Changes-Only download to the Maintenance Station.

Verification

Verify the successful exclusion of the field device:

Maintenance Station Runtime Navigation: Open the WinCC runtime on the Maintenance Station client. Navigate the diagnostic overview tree (@Diagnostic.pdl). Verify that the excluded field device or channel no longer appears in the equipment hierarchy.
Alarm Verification: Simulate a wire break or power loss on the excluded instrument. Confirm that no maintenance request or diagnostic alarm is posted to the Maintenance Station alarm list (@Maintenance_Alarm.pdl).
Process Operation Integrity: Verify that standard process graphics on operator clients continue to display the signal with appropriate quality codes without being interrupted by the maintenance view exclusion.

Limitations and Operational Precautions

Disabling diagnostic interrupts in HW Config suppresses hardware failure detection entirely for that module, meaning wire-break and short-circuit detection will not report to AS diagnostic buffers (OB82). Use Plant Hierarchy filtering or runtime Out of Service mode if you require the automation logic to detect faults while merely hiding the asset from supervisory Maintenance Station views. Always ensure that mandatory safety-related devices (e.g., F-I/O modules) are never stripped of diagnostic reporting.

Engineer FAQ

What is the difference between MS Standard and MS Basic in PCS 7?

MS Standard uses a dedicated WinCC Maintenance Station OS server to provide comprehensive plant-wide asset management with full diagnostic faceplates and electronic maintenance records. MS Basic integrates diagnostic screens directly into existing operator OS servers without requiring separate server hardware.

Will unchecking 'OCM' on a channel driver prevent process faceplates from opening?

No. The technological block (e.g., PIDConL, VlvL) retains OCM and opens its standard faceplate. Unchecking OCM on the underlying channel driver (Pcs7AnIn) or module driver (MOD_D16) only suppresses the specialized asset management diagnostic faceplate.

Can I temporarily exclude a device without recompiling and downloading the OS?

Yes. Use the APL 'Out of Service' mode on the device's channel or motor/valve block. Putting the block into Out of Service suppresses all maintenance alarms and flags the device as de-energized or isolated in Maintenance Station runtime.

Why do deleted devices continue to appear on Maintenance Station screens?

If hardware was removed but 'Create/Update Diagnostic Screens' was not executed, WinCC retains stale picture tree entries. Run 'Create/Update Diagnostic Screens' in Plant Hierarchy and compile the OS to cleanse orphan picture files.

Does disabling diagnostics on an ET 200 module affect other modules on the same rack?

No. Diagnostic interrupt configuration in HW Config is defined per individual module slot, allowing precise slot-by-slot control across distributed ET 200M or ET 200SP racks.