Web-HMI: Transforming Industrial Monitoring with OPC Data Access
Monitor and manipulate industrial data from ordinary PCs and mobile devices. Web-HMI brings factory floor data to your fingertips through secure, web-enabled streaming services.
The Evolution from Traditional HMIs
Traditional Approach
Conventional HMIs received factory data via field buses, requiring specialized hardware and limiting access to the physical device location.
Modern Solution
Web-HMIs transform ordinary PCs and PDAs into industrial monitoring stations, allowing remote access through secure login mechanisms with customized access rights.
Understanding OPC Data Access
Industry Standard
OPC (OLE for Process Control) provides uniform standards for industrial data exchange, developed by the OPC Foundation.
Hardware Independence
Eliminates coupling between software drivers and hardware, creating a universal communication method.
COM Architecture
Built on COM with Automation Wrapper DLLs that enable VBScript to invoke OPC server components from ASP pages.
Web-HMI Architecture
Industrial Equipment
Physical devices on the factory floor generating data
OPC Server
Collects and standardizes data from equipment
ActiveX Middleware
Connects web applications to OPC servers
Web Browser
Provides user interface for monitoring and control
Implementation Components
OPC Client ActiveX
Middleware component that activates the remote server and enables web connectivity
Configuration Data
Stores loading preferences via Excel sheets or database tables
XML Generation
Creates customizable viewing screens for remote administration
Server Scripts
ASP pages that invoke OPC server objects and display data
Server Configuration
Register ActiveX Component
Add the OLE wrapper DLL to COM+ application services to enable proper server communication.
Configure Process Isolation
Set the application to run the server in a separate process for improved stability and performance.
Load Configuration Data
Import device channels, locations, and other OPC items from database tables or Excel sheets.
Store Server Instance
Save the server object in the Application object of IIS to allow all clients to connect to the same instance.
Accessing Industrial Data
Real-Time Monitoring
View live industrial data through web pages that refresh to show current values from the factory floor.
Remote Control
Modify device settings and parameters through HTTP requests, with access controlled by user permissions.
Unit-Specific Views
Access different areas of the factory through dedicated pages (e.g., Unit1.asp) that display relevant devices.