STARTER and SIMOTION Scout cannot coexist on the same Windows installation. A clean STARTER V4.3.2 SP1 (or later) environment is mandatory before the web server context menu will reappear.

If a mixed SIMOTION + SINAMICS project is required, install STARTER and Scout on two separate physical or virtual machines. Running both inside the same Windows guest or partition is not supported and produces orphaned registry keys that break the web server add-in.

The web server is a single-listener service. It cannot be active on both X127 and X150 simultaneously. Confirm the drive's r8985 reports Web server active after the power cycle before opening a browser.

7. CompactFlash Card Web Server Files

The CU320-2 boots its web server from AWP files placed on the CF card by STARTER. The path layout is fixed:

/
|-- SIEMENS/
|   `-- SINAMICS/
|       `-- HMI/
|           |-- index.htm
|           |-- menu.htm
|           |-- start.htm
|           |-- ... (static AWP)
|-- USER/
|   `-- SINAMICS/
|       `-- HMI/
|           |-- user_define.htm
|           |-- ... (custom AWP)
`-- OEM/
    `-- SINAMICS/
        `-- HMI/
            |-- oem_define.htm
            |-- ... (OEM AWP)

When STARTER uploads the web server from the Web server > Upload pages command, it copies the Siemens-supplied baseline AWP set into /SIEMENS/SINAMICS/HMI/ on the CF card. User-defined pages go into /USER/SINAMICS/HMI/. A missing /SIEMENS/SINAMICS/HMI/index.htm is the most common reason the browser returns a 404 even though r8985 indicates the server is running.

To inspect the CF card, insert it into a Windows reader while the Control Unit is off; the card mounts as a removable drive. Never edit the Siemens baseline files directly - copy them to the USER tree and modify there.

8. Step-by-Step Configuration Procedure

8.1 Prerequisites

• Windows 10 (64-bit) or Windows Server 2016/2019 engineering PC.
• STARTER V4.4 (or V4.4 SP1) installed cleanly. No SIMOTION Scout on the same machine.
• CU320-2 DP or CU320-2 PN with firmware 4.6 (or 4.6 HF3) loaded.
• CF card with at least 512 MB free.
• Ethernet cable between engineering PC and X127 (or X150 for PN).
• Engineering PC IP address in the same subnet as the chosen CU320-2 port. For X127 default: 169.254.11.21 / 255.255.0.0.

8.2 Configuration Steps

1. Open STARTER V4.4 and open the CU320-2 project offline.
2. Right-click the CU320-2 drive object. Confirm the entry Web server > Activate is present. If absent, STARTER V4.3.2 SP1 has not been installed; reinstall STARTER.
3. Select Web server > Activate. The tool writes p8985[0] = 1 online and prompts for RAM to ROM.
4. Open the expert list and verify the parameter set:

   p8985[0] = 1   (web server enable)
   p8986    = 0   (X127) or 1 (X150)
   p8987[0] = 80  (HTTP port)
   p8987[1] = 0   (HTTPS off, recommended for first test)
   p8988    = 1   (standard authentication)

5. Set the interface IP address:
   • X127: p8901 = 169.254.11.23, p8903 = 255.255.0.0, p8904 = 0 (no router).
   • X150: p8920 = 192.168.1.13, p8922 = 255.255.255.0, p8923 = 192.168.1.1, p8924 = 1 (settings active).
6. Right-click the drive object and select Web server > Copy RAM to ROM.
7. Right-click and select Web server > Upload pages to push the Siemens baseline AWP set to the CF card.
8. Right-click and select Target system > Power cycle. Wait for the CU320-2 to complete its startup sequence (about 30-40 seconds). The READY LED turns green; the SF LED must be off.
9. Open a browser on the engineering PC and navigate to http://169.254.11.23/ (X127) or http://192.168.1.13/ (X150).

9. Verification

After the power cycle, confirm the listener is bound:

1. From the engineering PC, run ping 169.254.11.23 -n 4. The response must show <1 ms with no loss on the link-local subnet.
2. Open a command prompt and run curl -v http://169.254.11.23/. The HTTP response must be 200 OK and the body must contain the Siemens HMI banner. A 404 indicates the AWP files were not uploaded to the CF card.
3. In the STARTER expert list, read r8985. The value 1: web server active confirms the listener is up.
4. Open a browser, accept the standard authentication prompt, and verify the SINAMICS overview page loads. Test at least one drive object drill-down.

10. Troubleshooting Matrix

Symptom	Likely Cause	Action
Right-click menu has no Web server entry	SIMOTION Scout used or STARTER < V4.3.2 SP1	Install clean STARTER V4.4 on a separate Windows host
r8985 reports server active but browser 404s	AWP files missing from CF card	Use Web server > Upload pages in STARTER
Browser "connection refused" on port 80	p8986 binds to the other LAN port	Set p8986 to the port matched by the URL IP
Browser "Server Not Found" but ping works	Wrong interface or wrong subnet	Confirm browser URL IP matches p8986 port IP and subnet
HTTPS fails, HTTP works	Self-signed cert blocked by browser policy	Add security exception or use a CA-signed cert loaded via p8987[1]
Web server active until next power cycle then off	RAM only write, no ROM copy	Issue Copy RAM to ROM from the Web server menu
Authentication prompt loops	Wrong access level password or p8988 set to 0 with security enabled	Reset CU320-2 to factory defaults and re-enter the password
Browser hangs for 60 s then timeout	Engineering PC has two NICs and wrong one is routed	Disable the second NIC or add a static route for the link-local subnet
D435-2 works, CU320-2 does not	Tool was Scout for the D435-2 (a SIMOTION controller) and STARTER for CU320-2 projects, but used cross-licensed	Verify Scout is not being used to edit the CU320-2; create a fresh STARTER project
Web server active only on X127 even after p8986=1	PN variant required a PROFINET device name to take the X150 address	Assign a PROFINET name from TIA Portal or PLC project, then power cycle

11. Migrating From Firmware 4.5 to 4.6 HF3

The 4.5 to 4.6 jump is technically a minor release for the web server. The same parameter set applies. The two operational changes that affect this scenario are:

1. STARTER V4.3.x is no longer supported for online commissioning on 4.6 firmware. Upgrade STARTER to V4.4 (V4.4 SP1 recommended with HF3 hotfixes).
2. The web server add-in now requires the .NET Framework 4.7.2 runtime, which STARTER V4.4 installs as a prerequisite. If the install logs show a failure of the add-in, install .NET 4.7.2 manually before launching STARTER.

The 4.6 to 4.7 path is optional. 4.7 adds user-defined AWP variables and an OPC UA bridge for the web server, which is useful for an OEM demo but not required to expose the basic SINAMICS pages. STARTER V4.5 (or Startdrive V15) is the matching tool. The CF card web server files are compatible forward and back to 4.5; no re-upload is required for a downgrade.

12. Security and Network Hardening

The web server is unencrypted by default. Apply the following minimum hardening before exposing it beyond the service laptop:

• Set p8987[1] = 1 to enable HTTPS on port 443 and add a CA-signed certificate. Self-signed certificates are functional but generate browser warnings that fail automated tests.
• Set p8988 = 1 to require the SINAMICS access level password. The default user is Anonymous and the default password is empty if the access level is reset.
• Bind the web server to X127 only when possible. The link-local 169.254.0.0/16 range is not routed, so X127 is not reachable from a corporate network.
• If X150 is required, place the drive behind a managed switch port that limits inbound TCP to ports 80/443 and the PROFINET RT frames.
• Disable unused protocols on the same interface. PROFINET DCP, LLDP, and SNMP remain active on X150 even with the web server on; consult the SINAMICS S120 Communications Function Manual for parameter p8905 to mask services not in use.

13. References to Official Documentation

The full parameter description, AWP scripting reference, and CF card layout for the SINAMICS S120 web server are in the SINAMICS S120/S150 List Manual, function block chapter for the Control Unit. The SINAMICS S120 Function Manual contains the drive-side commissioning procedure. Both manuals are available on the Siemens Industry Online Support portal:

• Siemens Industry Online Support - entry point for the SINAMICS S120 product family, firmware downloads, and STARTER releases.
• SINAMICS S120/S150 List Manual - the canonical reference for all parameters including p8985 to p8988.
• SINAMICS S120 Web Server Commissioning Application Note - covers the upload of AWP pages and access through X127/X150.
• STARTER V4.4 Commissioning Tool Release Notes - confirms V4.3.2 SP1 as the first version to ship the web server add-in.

14. FAQ