Configuring WinCC V7 WebNavigator for LAN IP Address Access

Overview

SIMATIC WinCC V7 WebNavigator is the web-publishing option for the WinCC SCADA runtime. It allows thin-client HMI access to a running WinCC project from any Windows host on the LAN using only Internet Explorer/Edge with the WebNavigator ActiveX plug-in (legacy) or any modern browser via the WebNavigator plug-in download. The most common engineering error is treating WebNavigator as a standalone client application: it is not. The WebNavigator Server must be hosted on a WinCC single-user system, a WinCC Server, or a WinCC Client that owns its own WinCC project; thin clients only render pictures served by that machine.

This reference consolidates the configuration steps, license model, IP/DNS addressing rules, and the two failure modes reported in the field: (1) "WebNavigator only works on the local WinCC machine" and (2) communication loss to a SIMATIC HMI 477C panel after a host PC IP change from 192.168.0.30 to 192.168.0.100.

WebNavigator Architecture and Component Roles

Prerequisites

1. WinCC V7.0 SP3 or later (V7.4 / V7.5 recommended for current support matrix). See the SIMATIC HMI WinCC V7.5 WebNavigator entry (ID 109762744) for the official WebNavigator documentation bundle.
2. Microsoft IIS (Internet Information Services) installed and running on the WebNavigator Server host with the IIS-6 compatibility layer enabled.
3. A valid WebNavigator license dongle (USB hardlock) or license file on the server: one WebNavigator Server count plus one WebNavigator Client count per concurrent thin-client user.
4. TCP/IP reachable between the WinCC RT host and every WebNavigator Client. Default port 80 (HTTP) or 443 (HTTPS) must be open on the Windows Firewall of the server.
5. User accounts created in WinCC UserAdmin for each WebNavigator client user. Anonymous access is not supported for picture publishing in V7.
6. For LAN access by IP, both server and client must share a routable subnet (for example, 192.168.0.0/24). Avoid APIPA 169.254.x.x addresses on the server NIC.

Configuring the WebNavigator Server for LAN IP Access

1. Set a static IP on the WinCC host. Open Control Panel → Network and Sharing Center → Adapter Settings → IPv4 Properties. Replace any DHCP lease with a fixed address such as 192.168.0.30 and configure the subnet mask (255.255.255.0) and gateway. Document the address; the client browser will type this in the URL bar.
2. Install WebNavigator Server. From the WinCC V7 installation media run Setup and add WebNavigator Server. Restart the machine when prompted. The installer registers the WebNavigator virtual directory under IIS.
3. Configure the WinCC project to publish. In WinCC Explorer right-click WebNavigator → Web Configurator. On the General tab verify that the WebNavigator Server is enabled and the published port matches the firewall rule (default 80).
4. Define users in UserAdmin. Open WinCC Explorer → User Administration. Add each thin-client operator as a WinCC user, assign the WebNavigator Operator or higher authorization level, and set a password. The same credentials are entered in the client browser login dialog.
5. Open the inbound firewall ports. Run wf.msc and create two Inbound Rules: TCP 80 (HTTP) and TCP 443 (HTTPS) if SSL is in use. Restrict the scope to the LAN subnet (192.168.0.0/24) where possible.
6. Alias names vs. IP addresses. On the WebNavigator server the Web Configurator can publish under a host alias. To allow clients to connect by name (http://winccserver1) instead of http://192.168.0.30, enable Use alias names instead of IP addresses in the Web Configurator. Either DNS A-records or local hosts files on each client must resolve the alias.
7. Activate the WinCC project. From WinCC Explorer press the Activate button. The WebNavigator diagnostic page http://localhost/WebNavigator/Status.asp on the server must return a green status before client testing.

Connecting a WebNavigator Client via IP Address

1. On the client PC, open Internet Explorer 11 (legacy) or Microsoft Edge in IE Mode and install the WebNavigator plug-in when prompted. The plug-in install page is delivered automatically the first time the URL is opened.
2. Enter http://192.168.0.30 (substitute your server IP) into the address bar and press Enter. The browser downloads the WebNavigator ActiveX control if not already cached.
3. When the login dialog appears, enter the WinCC user name and password created in UserAdmin. Click Log On.
4. The published WinCC pictures should render inside the browser window. Tag values update over the standard WinCC channel polling.

Configuring WinCCViewerRT (RT Professional) for IP-Based Remote Access

When the runtime is WinCC RT Professional (TIA Portal) rather than classic WinCC V7, the same principle applies: the server publishes over HTTP and a thin viewer connects by URL. The official Siemens documentation describes the connection parameters as follows.

1. Install WinCCViewerRT on the remote PC (TIA Portal installation media or downloaded package).
2. Start the viewer and open the Parameters configuration tab.
3. Enter the Server address in the form http://<server name> or http://<IP address> (for example, http://192.168.0.30). Use HTTPS and port 443 if the server publishes with SSL.
4. Enter the WinCC user name and password assigned on the server.
5. Select the Runtime language and confirm whether automatic logon is allowed. Save and start the viewer.

The full procedure is documented in the Setting up WinCCViewerRT (RT Professional) manual page.

License Model and the "Maximum Number of Simultaneous Client Connections Reached" Error

The WebNavigator license model is concurrent-connection based. The total number of WebNavigator Client sessions plus one Diagnostics Client session cannot exceed the sum of WebNavigator Client counts installed on the server's license file or USB dongle.

Recovering HMI 477C Communication After an IP Change

The secondary failure mode in the field report is loss of HMI communication after the engineering PC was renumbered from 192.168.0.30 to 192.168.0.100. The SIMATIC HMI 477C (Multi Panel) stores its connection partner list in the WinCC flexible or ProTool project, not on the host PC. The host IP change does not affect the panel unless the panel was configured to initiate connections to that IP, but the panel-side project still references the old address in the channel configuration.

1. Identify the connection type used by the 477C. Open the WinCC flexible / TIA Portal project that was transferred to the panel and check Connections → [name]. Common types: SINUMERIK / SIMATIC S7 / SIMATIC HMI HTTP.
2. For an S7 MPI/Profibus connection to the PC: The 477C does not speak S7 to a PC IP address; this connection type is unaffected by the PC IP change. Re-check the HMI-to-CP cable and the panel's MPI/DP address.
3. For an Ethernet (TCP/IP) channel to the PC: Open the channel configuration and update the partner IP from 192.168.0.30 to 192.168.0.100. Rebuild the project and re-transfer it to the 477C using ProSave or the WinCC flexible transfer dialog.
4. For an HTTP / OPC / WinCC WebNavigator client role on the 477C: The panel itself is acting as a WebNavigator thin client. Update the URL it opens (http://192.168.0.100), then transfer the corrected project back to the panel.
5. Clear the connection cache on the panel. Power-cycle the 477C and confirm it boots without the "No connection to server" banner. On the panel the Control Panel → Transfer settings must still allow runtime changes if you want to test without re-transferring the project.
6. Validate with a ping from the panel. On the 477C, open Start → Programs → Command Prompt (or equivalent) and run ping 192.168.0.100. If the ping fails, the issue is the LAN path, not WinCC.

Troubleshooting Matrix

Verification Procedure

1. On the WebNavigator Server, open http://localhost/WebNavigator/Status.asp and confirm a green status indicator for each running WinCC runtime.
2. From a client PC on the same subnet, run ping 192.168.0.30 to confirm IP reachability.
3. Browse to http://192.168.0.30 in IE/Edge. Confirm the WebNavigator plug-in installs or updates, and the login dialog appears.
4. Log on with the test user and confirm at least one picture renders with live tag values updating at the configured acquisition cycle.
5. Trigger an alarm on the server and verify it appears in the client's message window within the configured refresh interval.
6. Close the browser and confirm the WebNavigator Server's session counter decrements (check Web Configurator diagnostics). If it does not decrement, a session leak is occurring that will eventually exhaust the client license count.

Field-Proven Caveats

• WebNavigator Server is not supported on a Windows PC that does not also run WinCC. Reports of "it worked from another PC" typically mean the user connected to a WinCC Client that happened to host the WebNavigator Server in addition to its own project.
• Alias names must be updated before the IP cutover. If you migrate the server from 192.168.0.30 to 192.168.0.100, enable alias names in the Web Configurator and point client bookmarks at the alias to avoid a multi-day rollout of new URLs.
• Anonymous access must remain disabled. WinCC V7 WebNavigator security is built on the WinCC UserAdmin database; turning on IIS anonymous authentication does not bypass the WinCC user check.
• The 477C is end-of-life. Migration to a SIMATIC Comfort Panel or TIA Portal project is the long-term path. Until then, keep a backup of the WinCC flexible project source so partner IPs can be edited without redrawing graphics.
• Firewall scope to the LAN subnet. Binding port 80 to Any is convenient but exposes the WebNavigator Server to the WAN. Bind it to the LAN subnet scope to limit exposure.