TP1500 Comfort to WinCC 6.0: OPC XML Gateway Configuration

Replacing a legacy MP370 Multi Panel with a current TP1500 Comfort panel while preserving an existing WinCC V6.0 SCADA station is a common migration problem on brownfield sites. The MP370 exposed data through an OPC XML Server that the SCADA consumed through the OPC XML Gateway. The TP1500 family ships with a fundamentally different OPC stack depending on firmware image version: panels with image < V13 still expose an OPC XML Server, while panels with image >= V13 expose only an OPC UA Server. Because WinCC V6.0 supports only OPC DA clients, the OPC UA server of a current TP1500 cannot be consumed natively. This reference documents the three viable engineering paths, the image-version switching procedure inside TIA Portal, the OPC XML Gateway installation and configuration, and the field-verification steps that confirm a stable legacy connection.

1. System Architecture Overview

The reference topology that this document targets is a single-engineer PC running WinCC V6.0 with an OPC DA client channel, an OPC XML Gateway (or OPC XML-DA Wrapper) installed locally, an Ethernet network, and a TP1500 Comfort panel configured as an OPC XML Server. Tag data originates in the PLC, is mirrored to the panel's internal tag database, and is then exposed by the panel's OPC XML server endpoint. The OPC XML Gateway on the SCADA PC terminates the XML/HTTP(S) traffic and re-publishes the data as classic OPC DA. The WinCC V6.0 OPC DA client connects to the gateway exactly as it did when the panel was an MP370.

2. Compatibility Matrix - TP1500 Image Versions vs OPC Server

The single most important selection when migrating from MP370 to TP1500 is the firmware image version loaded on the panel. The OPC stack is bound to the runtime image, not to the TIA Portal engineering version. The Comfort panel image is upgraded or downgraded independently of the TIA Portal project. The table below summarizes the OPC capability for each image branch observed on TP1500 Comfort hardware (6AV2 124-1MC01-0AX0 and successor part numbers).

3. Prerequisites

Before any panel image change, verify the following preconditions on both the engineering station and the SCADA PC.

3.1 Hardware and Part Numbers

• TP1500 Comfort panel, 15.6" widescreen, 6AV2 124-1MC01-0AX0 (or current equivalent 6AV2 124-1MC02-0AX0).
• SCADA PC with Windows 7 SP1 / Windows 10 LTSC, minimum 4 GB RAM, 100 GB free disk for the WinCC V6.0 project archive.
• Ethernet switch with at least two managed ports; PROFINET or standard Ethernet transport.
• One programming cable (USB or Ethernet) for the TIA Portal download and the panel image update via ProSave.

3.2 Software Requirements

• TIA Portal V13 SP1 (or higher) with the TP1500 Comfort HSP installed - required to be able to open the project, even if the deployed image is V12 or V11.
• WinCC V6.0 SP4 with the latest available hotfix (HF) and the OPC channel license (component AS-OS-OPC in the WinCC setup).
• OPC XML Gateway (component OPCXMLGateway) - located on the WinCC flexible 2008 SP3 / WinCC V7.0 installation media, or downloadable from the Siemens Industry Online Support portal under entry ID 22782588.
• ProSave V13 or later for image deployment to the TP1500 (located under Siemens\Automation\Portal V13\Data\Hmi\Transfer after TIA Portal install).
• OPC Scout V10 (Siemens) or Matrikon OPC Explorer for client-side verification.

3.3 Network Prerequisites

• Static IP addresses on both panel and SCADA PC. The TP1500 default is 192.168.0.1; assign at least 192.168.0.2 to the SCADA PC and place both on the same /24 subnet.
• TCP port 80 (HTTP) and 443 (HTTPS) opened between SCADA PC and panel for the OPC XML endpoint.
• DCOM defaults on the SCADA PC. The OPC DA portion of the chain uses DCOM/RPC on dynamic ports 1024-65535.

4. Solution Path Comparison

Three engineering paths solve the WinCC V6.0 / TP1500 mismatch. Each is sized against project constraints: cost, downtime, and SCADA longevity.

5. Path A - OPC XML Gateway with Downgraded Image

This is the lowest-risk, lowest-cost path. The TP1500 image is downgraded to expose the OPC XML Server, and the SCADA PC hosts the OPC XML Gateway. The WinCC V6.0 OPC DA client sees the same tag namespace it saw on the MP370.

5.1 Step-by-Step Procedure

1. Open the existing TIA Portal project for the TP1500. In the project tree, right-click the TP1500 device and select Properties > Change version / device. Select the older image version V12.0.0.0 (or V11.0.2.0). TIA Portal will re-compile the project against the older runtime; accept the warning about features that may be lost.
2. Compile and download the modified project to the TP1500 via Ethernet or USB. The transfer may take 8-12 minutes for a 15 MB Comfort project.
3. Verify the image version on the panel by navigating to Start Center > System > System Information > Image Version. Confirm it reads V12.0.0.0 or V11.0.2.0 before proceeding.
4. Enable the OPC XML Server on the panel: Control Panel > OPC Settings > OPC XML Server. Set the Activate checkbox, select the HTTP (or HTTPS) port, and bind to the panel's IP address. The default port is 80 for HTTP. Save and reboot the panel.
5. Test the XML endpoint from the SCADA PC using a browser. Navigate to http://192.168.0.1/SiemensOPCX (the service page should return a WSDL or HTTP 200). If the page is unreachable, check the Use router option in the HMI Control Panel.
6. Install the OPC XML Gateway on the SCADA PC. Run setup.exe from the WinCC flexible Runtime DVD or the downloaded package. During install, choose Custom and select the OPC XML Gateway component. A reboot is required.
7. Configure the OPC XML Gateway via Start > Programs > Siemens Automation > OPC XML Gateway > Configuration. Add a new OPC XML server entry with the URL http://192.168.0.1/SiemensOPCX and the security policy appropriate to your network.
8. Browse the gateway with OPC Scout V10. The local ProgID should appear as Siemens.OPCXMLDA.1 (or similar). Expand the tree to confirm all HMI tags are visible. If the gateway cannot browse, check the Windows Firewall rule for %ProgramFiles%\Siemens\OPCXMLGateway\Bin\OpcXmlGateway.exe.
9. Add the OPC DA channel in the WinCC V6.0 project: open WinCC Explorer, right-click Tag Management &emdash OPC, and add a new OPC DA connection. The WinCC OPC DA client should now display the gateway server in the OPC Server List.
10. Map the tags from the OPC XML gateway to the WinCC internal tag database. Tag names that begin with the panel's tag prefix (commonly HMI_ or DB_) are recreated 1:1 with the original MP370 names.

5.2 OPC XML Gateway Configuration Reference

6. Path B - Upgrade to WinCC V7.x with OPC UA

When the WinCC V6.0 station has reached end of support (Microsoft Windows XP Professional SP3 dependency, no SHA-2 support, no OPC UA), the cleanest path is a SCADA upgrade. This section documents the minimum required versions and the migration sequence.

1. Target SCADA version: WinCC V7.0 SP3 is the minimum that contains an OPC UA client channel. WinCC V7.4 SP1 (or V7.5 SP2) is recommended for new deployments and is the lowest version that interoperates cleanly with a TP1500 V14+ OPC UA server. Confirm that the V7.x license includes the OPC UA channel option.
2. Target panel image: TP1500 V13.0.0.0 or later. With V14 / V15 / V16 you also get a fully featured OPC UA server with certificates, authentication, and subscription support. The reference for image-specific OPC UA capabilities is the TIA Portal V20 documentation on WinCC Unified OPC UA server.
3. Enable OPC UA Server on the panel under Control Panel > OPC UA > Server. Select an authentication mode (Anonymous for testing, Certificate for production), assign a TCP port (default 4840), and apply.
4. Configure the OPC UA channel in WinCC V7.x. Open WinCC Explorer, right-click Tag Management, and add an OPC UA connection. Browse to opc.tcp://192.168.0.1:4840, import the panel's certificate if certificate-based auth is used, and accept the security policy.
5. Migrate the existing WinCC V6.0 project using the WinCC V7.x project migrator. Note that the OPC DA channel will be removed and replaced with the OPC UA channel; tag mapping is preserved, but quality codes and alarm classes may need re-validation.

7. Path C - Middleware PLC for Image Preservation

Path C is the only viable option when the TP1500 image must remain at V13+ (for example, when a customer has a global standard that prohibits downgrading panel images) but WinCC V6.0 cannot be upgraded. A middleware PLC exposes the same OPC DA interface the SCADA expects.

1. Add a SIMATIC S7-1200 or S7-1500 with an Ethernet interface, or repurpose an existing PLC that already aggregates process data.
2. Mirror the panel's HMI tags into a shared DB on the PLC. Use PUT/GET (S7-1200) or the partner-side DB read (S7-1500) - both are permitted on the OPC channel of the SCADA.
3. Configure the WinCC V6.0 OPC DA channel with the standard SIMATIC NET OPC server (component OPC.SimaticNET). The SCADA connects to the PLC directly; the panel image becomes irrelevant to the SCADA link.
4. Use the panel's own OPC UA server independently for any modern data consumers (MES, cloud, edge gateway).

8. Image-Version Switching Inside TIA Portal

The image-version switching operation is the same procedure used for any device-version change. Use it for both downgrading (Path A) and upgrading (Path B).

1. Open the TIA Portal project containing the TP1500.
2. Right-click the TP1500 in the project tree and choose Properties.
3. Select the General tab, then click Change device / version.
4. Choose Device version from the dropdown (V12.0.0.0 or V13.0.0.0 are typical targets). Confirm the firmware change.
5. Recompile the project. TIA Portal will warn about WinCC features that are not available in the older image; acknowledge each warning or remove the unsupported feature.
6. Download to the panel. Use Online > Download to device or ProSave if direct download is blocked by a firmware mismatch.

9. Verification Procedure

After completing Path A, perform the following checks in sequence. Each step is a hard gate; do not advance until the previous step passes.

1. Panel endpoint reachable: from the SCADA PC, open a browser to http://<panel-IP>/SiemensOPCX. Expect HTTP 200 or a valid WSDL response.
2. XML service document returned: invoke the OPC XML service document with a tool such as curl -X GET http://<panel-IP>/SiemensOPCX and confirm the response contains the service name OPCX or SiemensOPCX.
3. Gateway can browse: launch OPC Scout, connect to the local Siemens.OPCXMLDA.1 ProgID, expand the tree, and confirm at least one HMI tag is visible.
4. Quality code OK: subscribe to a known tag (for example, HMI_Heartbeat). Confirm the quality code is 0xC0 (Good) and the timestamp refreshes at the configured rate.
5. WinCC DA client reads: in WinCC V6.0 Graphics Designer, place a tag-prefixed I/O field linked to a panel tag. Confirm the runtime value updates without error.
6. Alarm round-trip: trigger an alarm on the panel and confirm it appears in the WinCC V6.0 alarm logging with the expected priority and class.
7. Endurance test: leave the SCADA running with the gateway for 24 hours. Inspect the gateway log for HTTP timeouts, DCOM errors, or reconnection storms.

10. Troubleshooting Matrix

11. Field-Commissioning Checklist

• Panel image version verified to be V12.0.0.0 (or chosen target) on the panel's System Information page.
• OPC XML Server enabled, HTTP / HTTPS port set, panel rebooted.
• OPC XML Gateway service is Started and set to Automatic in services.msc.
• OPC Scout successfully browses all configured tags with quality code 0xC0.
• WinCC V6.0 OPC DA channel shows Connected in the WinCC Channel Diagnostics tool (CCChannelDiag.exe).
• One representative tag is end-to-end animated in Graphics Designer to confirm runtime refresh.
• Alarm class mapping verified by triggering a known alarm on the panel.
• WinCC V6.0 archive is configured to dump every 60 seconds; the dump file size matches the configured tag count (sanity check).
• SCADA PC and panel both bound to a static IP, no DHCP lease dependency.
• 24-hour soak test completed with no reconnection events in the gateway log.

12. Performance and Sizing Notes

The OPC XML Gateway adds measurable latency compared to a direct OPC DA connection to a SIMATIC NET server. The dominant cost is the HTTP/SOAP framing of every read/write. On a 100 Mbit LAN with 500 tags at a 1-second refresh, expect gateway-side latency of 200-400 ms per poll cycle. For high-density or high-speed links (more than 2000 tags, sub-200 ms cycle), the direct OPC UA path (WinCC V7.4 SP1 + TP1500 V15+) outperforms the OPC XML Gateway by a factor of 3-5 because of subscription batching.

For a tag count N at a refresh rate T (seconds), the gateway bandwidth requirement can be approximated as:

bandwidth_kbps = (N * tag_payload_bytes * 8) / (T * 1000)

where tag_payload_bytes is approximately 320 bytes per tag (name + value + quality + timestamp + SOAP envelope). For N = 1000 tags at T = 1 s the link demand is approximately 2.56 Mbps, well within a 100 Mbit LAN. Avoid running the OPC XML Gateway across WAN links; the SOAP overhead and lack of compression make it unsuitable for sub-50 Mbps connections.

13. Standards and Reference Documentation

• WinCC Unified OPC UA Server (TIA Portal V20 documentation) - the authoritative source for OPC UA server capability on Unified Comfort panels (V18+).
• Siemens Industry Online Support forum entry 381795 - background discussion on TP1500 to WinCC OPC connectivity, including image-version caveats.
• OPC XML-DA Specification 1.01 - OPC Foundation, defines the SOAP/HTTP wire format used by the panel's V12 image.
• OPC UA Specification Parts 1-14 - OPC Foundation, defines the binary TCP transport used by V13+ images.