Configuring WinCC Flexible Runtime to S7-400 via CP443-1 Ethernet

Overview

This reference describes how to bring a WinCC flexible Runtime station (running on a SIMATIC IPC or third-party PC) online against a SIMATIC S7-400 controller through a CP443-1 Ethernet communications processor. The configuration paths shown apply to WinCC flexible 2008 / 2008 SP2 / SP3 / SP4 / SP5 and the matching STEP 7 V5.4 / V5.5 engineering toolset, all integrated inside the SIMATIC Manager.

The most common failure mode reported in the field is that the configured S7 connection between WinCC flexible RT and the S7-400 CPU shows status Offline / Disconnected even though the project was created inside STEP 7 and compiled without errors. The root cause in nearly every case is a mismatched Ethernet node type in the WinCC flexible RT station: the station is created with a generic IE General interface that does not advertise the S7 communication services required by WinCC flexible. Replacing the IE General node with an HMI IE node brings the connection online immediately.

Prerequisites

1. STEP 7 V5.4 SP3 or later (V5.5 recommended) with the HSP for the CP443-1 firmware installed.
2. WinCC flexible 2008 SP2 or later, integrated into the SIMATIC Manager so that the WinCC flexible ES appears as a sub-project of the S7 project.
3. SIMATIC S7-400 station with a CPU 41x-3 PN/DP or CPU 41x-4H and at least one CP443-1 in the central rack (UR1/UR2/CR2) or in an expansion rack with IM460/IM461.
4. SIMATIC IPC (e.g. IPC227G, IPC427D, IPC477D, IPC647C) or a panel PC with Windows XP SP3 / Windows 7 (32-bit) / Windows 7 Embedded Standard. WinCC flexible RT is certified for these operating systems per the WinCC flexible Release Notes.
5. Admin rights on the IPC for the WinCC flexible RT installation and for the SIMATIC Net / PC station configuration.
6. An Ethernet switch or direct patch cable (CP443-1 ↔ IPC) on the same IP subnet, plus valid IP addresses, subnet masks, and (if used) router addresses.

Network Topology

The reference architecture is a single Industrial Ethernet subnet that carries the S7 communication between the HMI station and the controller. Switched Ethernet (managed IE/PB switches from the SCALANCE XC/XB/XR family) is recommended for any installation that also carries PROFINET or that will scale beyond a single HMI.

Hardware Configuration of the S7-400 Station

Open the S7-400 station in HW Config and place the CP443-1 in a free slot. The slot is required later for the S7 connection target. A common arrangement is:

Double-click the CP443-1 to open Properties – CP 443-1. Configure the IP address, Subnet mask, and (optionally) a router. Under Ethernet -> Network Settings, enable the protocols used by WinCC flexible:

• ISO-on-TCP (RFC1006) – required for S7 communication via the S7-protocol family. This is the default transport used by WinCC flexible when the HMI IE node is selected.
• TCP/IP (native) – only required for S7 connections using the open TCP/IP variant (rarely used with WinCC flexible).
• Send / Receive mailbox – not used by WinCC flexible; can stay disabled.

Adding the WinCC flexible RT Station to the STEP 7 Project

Inside the SIMATIC Manager, insert a new station that represents the IPC:

1. Right-click the project → Insert New Object → SIMATIC PC Station.
2. Open HW Config for the new PC station. By default the catalog offers an IE General interface under SIMATIC PC Station -> CP & IF -> IE. Delete this IE General entry; the IE General node does not carry the WinCC flexible S7 protocol and the connection will never reach the S7-400.
3. Insert an HMI IE interface instead: SIMATIC PC Station -> HMI -> HMI IE. Place it in slot 1 (or the slot reserved for the HMI software). The HMI IE node has the S7-on-TCP service active and is the node that WinCC flexible Runtime expects to bind to.
4. Set the IP address of the HMI IE node to match the IPC's industrial Ethernet adapter (for example 192.168.0.10 / 255.255.255.0).
5. Save and compile the PC station (Station → Save and Compile). The compiled configuration is exported as a *.pc file* and downloaded to the IPC with the PC Station Configuration Editor or via Station Configuration -> Import Station from a WinCC flexible project that uses the same STEP 7 integration.

Configuring the S7 Connection in NetPro

With the PC station (HMI IE node) and the S7-400 station (CP443-1) both inserted in the project, open NetPro. The HMI IE node on the PC station and the CP443-1 on the S7-400 station should each show a green S7 endpoint indicator when the compiled configurations match. Add an S7 connection as follows:

1. Select the HMI IE node on the PC station row.
2. Right-click → Insert New Connection → partner: the S7-400 station, type: S7 connection.
3. In the connection properties dialog verify the parameters:

Save and compile NetPro. The connection is now part of the STEP 7 project; it is not yet active on the IPC, only on the ES.

WinCC flexible Connection Configuration

Open the WinCC flexible project that is integrated under the PC station. Switch to Project → Communication → Connections. Because WinCC flexible is integrated into STEP 7, the S7 connection you just created in NetPro is offered as a choice. Add a new connection of type SIMATIC S7 300/400 and point it to the existing NetPro connection S7_HMI_to_400.

If WinCC flexible is being used standalone (without STEP 7 integration), create the connection manually:

The Partner slot value must point at the CP443-1, not at the CPU. WinCC flexible routes the S7 frames through the Ethernet CP; the CP443-1 in turn forwards them to the CPU over the backplane. If the slot is wrong the connection setup will be refused by the CP.

Downloading the Configuration to the IPC

1. On the IPC, install the SIMATIC Net PC software that matches the WinCC flexible RT version (or, for the integrated case, the SIMATIC Net that ships with STEP 7 V5.x).
2. Start the Station Configuration Editor (Start → SIMATIC → SIMATIC NET → Configuration → Station Configuration Editor). The HMI IE node and its index correspond to the one defined in HW Config of the PC station.
3. Import the compiled PC station configuration: Station → Import Station, then select the *.pc file generated by NetPro.
4. Start WinCC flexible Runtime. The status bar of the project must show the connection as Online; tags are polled from the CPU.

Verification

After the runtime starts, run the following checks in order. Each step gives a quick pass/fail signal that pinpoints the layer at which a fault lives.

1. Layer 1 (cable/port): The link LED on the CP443-1 and on the IPC Ethernet adapter must be lit. If it is off, replace the patch cable or the SFP (SCALANCE fiber ports).
2. Layer 3 (IP): From the IPC open a command prompt and run ping 192.168.0.20. A reply confirms the subnet; a timeout means the wrong IP, no default gateway, or VLAN separation.
3. S7 endpoint (Station Config): The Station Configuration Editor must show the HMI IE module as Configured and Running. If the module stays in Fault, the SIMATIC Net installation does not include the HMI IE driver or the imported *.pc file does not match the installed SIMATIC Net version.
4. WinCC flexible status: Start the runtime in Configuration mode (WinCC flexible RT → File → Start Runtime). Open the connection diagnostics via Tools → Status of Connections. A green check next to the S7 connection means the S7 handshake completed; the OPC/area pointers (date/time, job mailbox) should also be green.
5. Tag test: Configure a tag, e.g. DB1.DBD0, and display it in a screen with the Output field configured to refresh every second. The value must follow the value in the CPU online watch table.
6. PG diagnostic: From STEP 7, choose PLC → Diagnostics → Operating Mode and then PLC → Module Information on the CP443-1. The connection list must show an established S7 connection from the IPC.

Troubleshooting Matrix

Variant: Standalone WinCC flexible (No STEP 7 Integration)

If the WinCC flexible project is edited on a workstation without STEP 7 integration, the Connections editor in WinCC flexible is the only place to define the S7 link. Use the same parameters as the integrated case (table above), but be aware that:

• The PC station configuration must be set up manually on the IPC using the SIMATIC NET Configuration Console, mapping the WinCC flexible S7ONLINE channel to a physical Ethernet adapter.
• No *.pc file is generated; the S7 connection exists only inside the WinCC flexible project.
• Two ES stations editing the same project must not differ on the S7 connection parameters; the project always loads on the IPC with the values that were last compiled in the project.

Variant: Redundant S7-400 (H-CPU) and CP443-1 Advanced

With a redundant S7-400 (CPU 41xH) and a CP443-1 Advanced (6GK7443-1EX40-0XE0), WinCC flexible connects to the active CPU through the single IP address that the H-system exposes (the CP443-1 Advanced does the failover). No changes are required on the WinCC flexible side; only the STEP 7 project must contain both H-CPUs and the redundancy configuration compiled in HW Config.

Commissioning Checklist

• CP443-1 firmware and STEP 7 HSP versions match (see STEP 7 Readme for the supported CP443-1 versions).
• PC station in HW Config uses an HMI IE node, not IE General.
• NetPro connection points at the CP443-1 slot, not at the CPU slot.
• WinCC flexible RT connection type is SIMATIC S7 300/400 with S7ONLINE access point.
• Set PG/PC interface on the IPC is S7ONLINE (STEP7) → <IPC LAN adapter>.
• SIMATIC NET version on the IPC matches the STEP 7 version used to compile the *.pc file.
• Windows Firewall allows the S7DOS service and the WinCC flexible RT process.