Configuring and Troubleshooting MHTML NoteView in PCS 7 V9.0 SP2 APL Faceplates

In SIMATIC PCS 7 V9.0 SP2 (and higher), the NoteView (Memosicht) feature in Advanced Process Library (APL) faceplates allows operators to view formatted rich-text documents and standard operating procedures (SOPs) encoded in MHTML (.mht) format. To implement NoteView, author the document, save it as an MHTML file encoded in UTF-8, and place it in the project folder under GraCS/NoteView. On the technological block (such as MonDi8 or MotL), specify the filename in the NoteView configuration attribute. If clicking the document in runtime opens a blank window, the issue is typically caused by WinCC ServiceMode restricting interactive desktop permissions, Internet Explorer Enhanced Security Configuration (IE ESC) blocking active web controls, or malformed MHTML headers. Furthermore, file synchronization between ES and OS is additive; deleted ES files must be purged manually from target OS stations.

Executive Summary

Modern process automation faceplates serve not only as real-time control portals but also as contextual knowledge repositories for plant operations. In PCS 7 V9.0 SP2, Siemens introduced formatted MHTML support for the APL NoteView (Memosicht), replacing legacy plain-text memo boxes with rich web documents capable of displaying operating instructions, chemical safety data sheets, and wiring diagrams directly inside WinCC faceplates. However, commissioning engineers frequently encounter blank popup windows or file synchronization discrepancies between the Engineering Station and target OS servers. Understanding how the Windows WebBrowser ActiveX container, Internet Explorer security zones, and OS Project Loader interact ensures reliable document presentation.

Architecture and Fundamental Mechanics

The document rendering and storage architecture of APL NoteView operates across defined software tiers:

The MHTML (MIME Encapsulation) Format:
* MHTML (.mht or .mhtml) bundles an entire HTML document—including embedded CSS styles, vector graphics, and base64-encoded images—into a single self-contained file.
* APL faceplates use this single-file container to ensure all images and text load reliably from a single directory location.
The WinCC Graphics Container Architecture:
* Inside the APL faceplate standard view (@PG_..._NoteView.pdl), WinCC embeds the standard Microsoft WebBrowser ActiveX control (shdocvw.dll / mshtml.dll).
* When the operator clicks the document name in the faceplate list, the VBScript handler passes the URI path (file:///.../GraCS/NoteView/doc.mht) to the WebBrowser container.
Root Causes of Blank Rendering Windows:
* WinCC ServiceMode: When an OS Server runs in ServiceMode (as a non-interactive background Windows service), Windows isolates desktop drawing contexts (Session 0). If Graphics Runtime is viewed remotely without interactive user rights, the WebBrowser container fails to initialize, rendering an empty white box.
* Internet Explorer Enhanced Security (IE ESC): On Windows Server 2016/2019, IE ESC blocks local active scripting and ActiveX instantiation within the file:// protocol zone.
* Malformed MIME Headers: Simply renaming an .html file to .mht in Windows File Explorer does not generate valid MIME headers; the browser engine detects the corrupt format and aborts rendering.
The Additive ES-OS File Synchronization Mechanism:
* When an OS is compiled or downloaded (PLC > Download), the Project Loader copies new or modified files from the ES GraCS/NoteView folder to the target OS.
* However, this transfer is strictly additive: if an engineer deletes an obsolete .mht file on the ES, the target OS retains its local copy, causing deprecated files to linger in the runtime list.

Step-by-Step Implementation Procedure

Follow these procedures to create, deploy, and troubleshoot MHTML NoteView documents in PCS 7 V9.0 SP2:

Create and Save Valid MHTML Documents:
* Author your operating instructions in Microsoft Word, an HTML editor, or web browser.
* In the browser or editor, select File > Save As....
* Choose Web Archive, single file (.mht; .mhtml).
* Ensure document encoding is set to UTF-8 (not ASCII or ANSI).
* Name the file concisely without spaces or special symbols (e.g., SOP_MonDi8_PumpFault.mht).
Place File in Project Directory on the ES:
* In Windows File Explorer, browse to your PCS 7 project directory:
<Project_Path>/<OS_Name>/GraCS/NoteView/.
* (If the NoteView folder does not exist, create it inside GraCS).
* Copy your .mht files into this directory.
Configure Block Properties in CFC:
* Open the target technological chart in CFC (e.g., containing MonDi8 or MotL).
* Open block properties and locate the parameter or attribute associated with NoteView (e.g., under the block's Configuration / Memo parameters).
* Enter the exact filename: SOP_MonDi8_PumpFault.mht.
Download to OS Stations:
* Right-click the OS project in SIMATIC Manager and select PLC > Download (Scope: Changes only or Entire OS).
* The download engine copies the GraCS/NoteView directory to all target OS Servers and Clients.
Resolve Blank Screen Issues on Windows Server:
* On the target OS Server / Client, open Server Manager.
* Under Local Server, locate IE Enhanced Security Configuration (IE ESC).
* Set IE ESC to Off for Administrators (or configure Trusted Sites zone to allow file://*).
* Open Internet Options (inetcpl.cpl), navigate to the Security tab, select Local Intranet, click Custom level..., and verify that Active scripting and Run ActiveX controls are set to Enable.
Manual Cleanup of Obsolete OS Files:
* Because OS downloads are additive, if a file was deleted on the ES, log onto each target OS Server and Client and manually delete the obsolete .mht file from <OS_Path>/GraCS/NoteView/.

Verification

In WinCC Runtime, open the faceplate for the configured MonDi8 block. Click the NoteView (Memosicht) tab. Verify that SOP_MonDi8_PumpFault.mht appears in the document selection dropdown or list. Click the document; confirm that the browser window renders formatted headings, rich text, and embedded process diagrams cleanly within 1 second. Open the same faceplate on an OS Client; verify identical rendering.

Limitations and Operational Precautions

MHTML NoteView is only available starting in PCS 7 V9.0 SP2; earlier versions support only plain-text notes. Avoid embedding massive high-resolution bitmap images, as opening large MHTML files (> 10 MB) can cause momentary faceplate rendering lag in runtime.

Engineer FAQ

Which PCS 7 version first introduced MHTML NoteView?

Support for formatted MHTML (.mht) documents in APL NoteView was introduced in PCS 7 V9.0 SP2.

Why does the NoteView window open completely blank?

Blank windows typically occur if the file is not a valid MIME-encoded MHTML file, if IE Enhanced Security Configuration (IE ESC) blocks local script execution, or if running under non-interactive ServiceMode.

Can you simply rename a .html file to .mht?

No. A true MHTML file requires multi-part MIME boundary headers and base64 encoding; saving directly from a browser or Word as 'Single File Web Page' is required.