3.21.3

Alarm Shelving and Suppression (IEC 62682)

WinCC OA now provides alarm shelving and suppression capabilities based on IEC 62682 / ISA 18.2 standards. The new AlertService enables three complementary alarm management mechanisms:

• Alarm Shelving: Operators can temporarily hide individual alert instances from the active alert list. A configurable timer automatically restores shelved alerts after the shelving period expires.
• Suppression by Design: Engineers can suppress alert handler configurations at the datapoint level to prevent alert generation during commissioning or planned maintenance.
• Out-of-Service Mode: Datapoint elements can be placed into maintenance mode by swapping alert classes to dedicated maintenance counterparts (alarm-maint, warning-maint, info-maint). Alerts continue to be generated but are visually distinguished and excluded from operational KPIs.

All actions are logged as Security Events and provide a complete audit trail. Dedicated overview panels for shelved alerts, suppressed handlers, and out-of-service objects are accessible from the Alert Event Screen.

See Alarm shelving and suppression overview for details.

WebUI Runtime

• The new WebUI Runtime provides a modern web development framework for building standalone web pages and applications on top of WinCC OA. Based on Lit Web Components and TypeScript, it connects to the backend via WebSocket using the OaRxJsApi for real-time datapoint access. Pages are served by the webserver.js and integrate seamlessly into the existing Dashboard. The framework includes a shared bundle architecture, configurable navigation, theming and branding support, and is optimized for AI-assisted development workflows. See WebUI Runtime.

CTRL

• New AlertService functions: AlertServiceClient::shelveAlerts(), AlertServiceClient::suppressAlerts(), AlertServiceClient::setOutOfService() and their corresponding reverse operations.

Disaster Recovery System

• DRS project file synchronization now uses a network share instead of shared project folders, improving security. The synchronization reuses the export path configured in the DRS wizard (Step 4) and automatically creates the subdirectories FileSync and SubFileSync on the network share. This eliminates the need for individual projects to access other project folder structures. See Configuration - Step 5 - Project File Synchronization.

Web Connectivity

• The new webserver.js backend is available as a Node.js-based web server running inside the JavaScript Manager. It provides HTTPS and WebSocket communication on a single port and serves as the recommended backend for the Dashboard and custom web applications. Customer extensions are supported via TypeScript and CTRL handlers using the @wincc-oa/backend npm package.

UI

• VarTrend: Configurable downsampling is now available for NGA projects, improving data visualization performance.
• Automatic _MemoryCheck threshold calculation now adapts dynamically to the target system hardware.

Drivers

• Modbus: The driver now supports the Output Single direction, allowing a single bit to be written to a register while all other bits are set to 0.

Northbound Manager

• Sparkplug B: The protocol now supports a configurable MQTT keep-alive timeout through the mqttkeepalive parameter in <nbm_instance>.Config.Protocol (default: 60 seconds).