Configuring Festo PS1-HC20-60 OPC Communication with WinCC

Overview

Field installations that pair a Festo PS1-HC20-60-FST industrial PC controller with a Siemens WinCC HMI/SCADA runtime rely on an OPC server to bridge the controller's native protocol with the HMI's tag database. The PS1-HC20-60-FST is a member of Festo's legacy IPC controller family, which predates the modern Festo AX Controls platform. Bridging this hardware to current HMI/SCADA stacks requires an OPC Classic DA server (Festo Easy OPC Server) or a third-party OPC UA gateway that wraps the controller's serial/Ethernet protocol. This reference documents the legacy path using the Festo Easy OPC Server demo and outlines the modern migration route through OPC UA and the CPX-E automation system.

Problem Definition

Engineers commissioning WinCC against a Festo PS1-HC20-60-FST typically report the following:

• No native WinCC driver exists for the PS1-HC20-60-FST under the Siemens channel selection tree.
• The Festo controller exposes its data set over a proprietary Festo bus protocol on Ethernet or RS-232, not over S7 MPI/Profibus/Profinet.
• Direct ActiveX/OPC integration is required because WinCC's "SIMATIC S7 Protocol Suite" channel cannot browse PS1 tags.
• The Festo-supplied Easy OPC Server is a demo binary that must be evaluated for tag count and runtime behavior before production deployment.

Hardware Identification: PS1-HC20-60-FST

The part number decodes as follows per Festo's catalog convention:

The PS1-HC20-60-FST uses the Festo FST firmware shell, which exposes process variables over a TCP-based Festo bus protocol (typically port 1900 or configurable) plus an RS-232 service port for engineering access. The controller's native programming environment is Festo's FST toolchain, which stores tag definitions in a project file consumable by the Easy OPC Server.

Communication Stack Options

Three viable paths exist for moving PS1-HC20-60-FST data into WinCC:

1. Festo Easy OPC Server (Classic DA) — direct path; reads tags via Festo bus and serves them through OPC DA 2.0/3.0. WinCC consumes via the OPC DA channel.
2. Third-party OPC DA/UA gateway — products such as KEPServerEX, MatrikonOPC, or Softing's opc4s7/Festo plug-in present the Festo bus as either OPC DA or OPC UA. WinCC Professional can connect natively as an OPC UA client.
3. Custom ActiveX container with FBD/FST runtime — embedded WinCC Global Script C/VBS that drives an ActiveX wrapper around the OPC DA automation interface. Used when the HMI is locked to legacy WinCC V6.x.

Festo Easy OPC Server — Installation and Configuration

Prerequisites

• Windows 7 SP1 / Windows 10 (32-bit preferred; 64-bit requires the WoW6432 mode flag in DCOMCNFG).
• Administrator rights for DCOM registration.
• Festo Easy OPC Server installation package — historically distributed as opc_easyserver_demo.exe by Festo. Verify the current download location on the Festo product portal under legacy downloads.
• Network reachability between the WinCC station and the PS1-HC20-60-FST controller on the Festo bus port.

Step-by-Step Configuration

1. Install the Easy OPC Server. Run the installer as Administrator. The package registers the COM server under ProgID = Festo.EasyOPC.1 and drops the configuration tool FestoEasyOPCConfig.exe into %ProgramFiles%\Festo\EasyOPC.
2. Import the FST project. Open the configuration tool and load the PS1 project's .fst export. The server reads the symbol table and creates one OPC tag per named variable.
3. Configure the channel. Set the controller IP address, port (default 1900), and polling interval. Recommended start: PollRate = 250 ms, DeadBand = 1% for analog tags.
4. Test connectivity. Use the configuration tool's built-in Read/Write Test pane to verify each tag round-trips. Resolve any tag marked BAD_QUALITY before moving on.
5. Configure DCOM. On the WinCC station open dcomcnfg.exe, navigate to Component Services → Computers → My Computer → DCOM Config, locate Festo.EasyOPC.1, and grant launch and access permissions to the WinCC runtime user account (typically SIMATIC HMI or the local service identity).
6. Add OPC channel to WinCC. In the WinCC Explorer, add a new driver of type OPC → OPC DA. Browse the local server, pick Festo.EasyOPC.1, and import the tag list.
7. Map to HMI tags. For each OPC item create a WinCC internal or process tag. Use the naming convention PS1_<areaname>_<tagname> for traceability.
8. Activate runtime. Start the Easy OPC Server service first, verify it shows Running in the system tray, then start WinCC Runtime.

WinCC Channel Configuration Reference

Troubleshooting Matrix

Modern Migration Path: OPC UA and Festo AX Controls

Long-term support for the PS1-HC20-60-FST is constrained. Festo's current automation platform, Festo AX Controls, unifies mechanics, commissioning, programming, and AI optimization on a single real-time runtime. New deployments should target:

• CPX-E automation system — high-performance controller platform; see the CPX-E documentation for hardware and OPC UA server specifications.
• Festo AX Controls server — exposes an OPC UA endpoint natively, eliminating the Classic DA bridge.
• WinCC Unified / TIA Portal — OPC UA client channel; browse the AX Controls endpoint at opc.tcp://<ax-controller>:4840.

The architectural rationale is documented in OPC Connect: Connecting PLCs to Various Software Packages with OPC UA, which describes the modern pattern of an embedded OPC UA server in the PLC and an embedded OPC UA client in the HMI/SCADA package.

Migration Bridge for Existing PS1 Fleets

1. Deploy an industrial gateway (e.g., Softing edgeConnector, Kepware, or HMS Anybus X-gateway) on the line.
2. Configure the gateway as an OPC DA client toward the legacy Easy OPC Server.
3. Expose the gateway's OPC UA server endpoint to WinCC Unified.
4. Phase out the PS1 controller during scheduled downtime, replacing with a CPX-E running AX Controls.
5. Re-point WinCC tag database to the new OPC UA endpoint via a redirect script.

Verification Procedure

1. From the WinCC station, open the OPC DA client test utility (e.g., OPC Quick Client shipped with the Easy OPC Server).
2. Confirm Server State = Running and that the imported tag tree is fully browsable.
3. Read three representative tags: one digital input, one analog input, one calculated float. Each should return Good quality within 500 ms.
4. Write a value to a non-critical tag from the WinCC test screen and verify the change reaches the controller.
5. Force a controller-side fault and confirm WinCC reports BAD_QUALITY on affected tags within two poll cycles.
6. Check the Windows event log for COM errors after a 1-hour soak test.

Field-Proven Caveats

• Demo license limitations: The free opc_easyserver_demo.exe enforces a tag-count cap and a runtime nag screen. Do not deploy in production without licensing.
• DCOM hardening: Windows DCOM defaults tightened in Windows 10/11 may block remote OPC calls. Open Component Services → My Computer → Properties → Default Properties and enable Enable Distributed COM on this computer.
• Festo bus poll rate: Setting the OPC server poll rate below 100 ms can saturate the Festo bus and starve the controller's own cycle time. Keep PollRate ≥ 200 ms.
• ActiveX deprecation: Microsoft has deprecated ActiveX controls in Microsoft Edge and modern Office. If your HMI relies on an ActiveX host for the OPC bridge, lock the runtime to Internet Explorer mode or migrate to a .NET-based OPC UA client.
• Firewall on the WinCC station: Allow inbound on the dynamic RPC port range (49152–65535 default) and outbound to TCP 1900 on the controller.

Standards and Specifications Reference

FAQ