Operating S7-400H Controllers with CP 1623 and WinCC V7.4 on Windows Server 2012 R2 in SIMATIC PCS 7

In SIMATIC PCS 7 v8.2, operating a redundant S7-400H automation system with WinCC V7.4 and a CP 1623 communications processor on a Windows Server 2012 R2 (64-bit) operating system is fully supported and certified. Establishing communication requires installing SIMATIC NET PC Software V14 (bundled on the PCS 7 v8.2 DVD), deploying STEP 7 V5.5 SP4 Hotfix 11 or higher, configuring a fault-tolerant S7 connection in NetPro, and installing a valid 'SIMATIC NET HARDNET-IE S7 REDCONNECT' license in Automation License Manager (ALM).

System Compatibility and Windows Server 2012 R2 Prerequisites

Deploying modern SIMATIC PCS 7 v8.2 operator stations frequently pairs enterprise server operating systems with high-availability automation controllers:
- Operating System Baseline:
* Windows Server 2012 R2 Standard Edition (64-bit) is the certified server platform for PCS 7 v8.2 and WinCC V7.4 OS Servers.
- CP 1623 PCI Express Adapter:
* The CP 1623 (6GK1162-3AA00) interfaces via PCI Express (x1 lane).
* Its onboard microprocessor executes the communications protocol stack independently of Windows operating system threads, shielding real-time S7 communication from Windows CPU spikes.
- STEP 7 Kernel Alignment:
* Managing S7-400H controllers (6ES7414-5HM06-0AB0, 6ES7416-5HT06-0AB0, or 6ES7417-5HT06-0AB0) within PCS 7 v8.2 requires STEP 7 V5.5 SP4 with at least Hotfix 11, ensuring full support for 64-bit device drivers and S7 Redconnect routing.

The Role of SIMATIC NET HARDNET-IE S7 REDCONNECT

Commercial Accuracy Disclaimer: Software order numbers (MLFBs), package structures, and hardware capacity prerequisites vary across PCS 7 versions and hardware platforms. System integrators must confirm exact software entitlements and licensing requirements against the official Siemens Catalog CA 01 and obtain an authorized Siemens distributor quotation prior to purchasing.

Connecting an OS station to an S7-400H redundant pair over Industrial Ethernet requires specialized software handling:
1. Redundant Path Management:
- The S7-400H possesses two independent central controllers (Rack 0 and Rack 1), each equipped with a CP 443-1 communications processor.
- A standard S7 connection binds to a single IP address. If the active CPU or cable drops, communication is lost.
2. REDCONNECT Dynamic Switchover:
- SIMATIC NET HARDNET-IE S7 REDCONNECT monitors all four physical paths between the dual CP 1623 ports and the dual CP 443-1 modules.
- In the event of a cable break, switch failure, or CPU failover, REDCONNECT executes an instantaneous, bumpless switchover to the surviving communication path in under 100 ms without interrupting WinCC Runtime.
3. Mandatory License:
- The license key HARDNET-IE S7 REDCONNECT (e.g. MLFB 6GK1716-0HB14-0AA0 for V14) must reside in Automation License Manager (ALM) on the OS Server.

Step-by-Step Fault-Tolerant Connection Configuration

To configure the redundant connection between WinCC V7.4 and S7-400H:

Configure PC Station in SIMATIC Manager:
- Insert a SIMATIC PC Station in Component View.
- Open HW Config:
- Slot 1: WinCC Appl. (WinCC Application).
- Slot 2: CP 1623 (set MAC and IP address on the Industrial Ethernet subnet).
- Save and compile HW Config.
Configure Fault-Tolerant S7 Connection in NetPro:
- Open NetPro.
- Select WinCC Appl. in the PC Station.
- In the lower connection table, right-click and select Insert New Connection.
- Select the target S7-400H station.
- Under Type, select Fault-tolerant S7 connection.
- In connection properties, verify that all four sub-connection paths are enabled (Active).
- Compile NetPro: select Network > Save and Compile > Check completely.
Download NetPro and PC Station:
- Download the network configuration to both the S7-400H CPU and the local PC Station via the Station Configuration Editor.
Compile the WinCC OS Project:
- In SIMATIC Manager, compile the OS project.
- In WinCC Explorer, open Tag Management > SIMATIC S7 PROTOCOL SUITE > Named Connections.
- Confirm that the fault-tolerant connection name appears with its S7 redundant channel DLL active (CCAxS7RedConnect.dll).

S7-400H to WinCC V7.4 Redundant Communication Matrix Table

The following table details the hardware and software layers required for redundant communication:

Layer / ComponentPhysical / Logical EntityRequired Version / SettingFunction in ArchitectureOperating SystemWindows Server 2012 R264-bit Standard EditionHosts WinCC V7.4 OS Server RuntimePC Communications HardwareCP 1623 PCIe Card6GK1162-3AA00Hardware coprocessor; offloads ISO/TCP stackSIMATIC NET SoftwareSIMATIC NET PC SoftwareVersion 14 (or V13 SP2)Provides device drivers and NDIS protocolsRedundancy LicenseALM License KeyHARDNET-IE S7 REDCONNECTEnables bumpless 4-path communication switchoverController HardwareS7-400H Dual RackFirmware V4.5 / V6.0Redundant automation control processingController InterfaceCP 443-1 (Dual modules)6GK7443-1EX30-0XE0Industrial Ethernet communication interfaces

Verification

To confirm that fault-tolerant communication is operational and bumpless:
1. In Windows Start menu, launch Siemens Automation > SIMATIC > WinCC > Tools > Channel Diagnosis.
2. Expand Named Connections: verify that the connection status displays a green checkmark and reports State: OK.
3. Open WinCC Runtime: confirm that faceplates and process trends are actively updating.
4. Perform a live redundancy test:
- Unplug the Ethernet cable from CP 443-1 on Rack 0.
- Observe the operator faceplates: verify that process values do not display disconnected states (no yellow question marks).
- Check WinCC Channel Diagnosis: confirm that sub-connection switched seamlessly to Rack 1 without losing a single data cycle.
5. Reconnect the cable and verify automatic sub-path recovery.

Limitations and Operational Precautions

When managing S7 Redconnect configurations:
1. Never Use Standard SOFTNET Licenses: Standard SOFTNET-IE S7 does not support fault-tolerant S7 connections. Attempting to use SOFTNET will cause WinCC to drop communication whenever the S7-400H switches master racks.
2. Matching Firmware Levels on Controller CPs: Both CP 443-1 modules on Rack 0 and Rack 1 must share identical hardware MLFBs and firmware releases to prevent asymmetric communication timing.
3. Proper Grounding of CP 1623: Ensure the PC chassis is connected to low-impedance earth ground. Floating chassis potentials induce high-frequency common-mode noise across the PCI Express bus, triggering sporadic adapter resets.

Engineer FAQ

Can I run WinCC V7.4 with CP 1623 without an S7-400H controller?

Yes. CP 1623 can communicate with standard non-redundant S7-300 and S7-400 controllers using standard S7 connections via the HARDNET-IE S7 license (without Redconnect).

Why did NetPro prevent me from selecting 'Fault-tolerant S7 connection'?

This occurs if the partner PLC is configured as a standard S7-400 instead of an S7-400H redundant station, or if the PC station was configured with a standard commercial NIC (IE General) without the required Redconnect software package.

What is the difference between CP 1613 and CP 1623?

CP 1613 used a legacy 32-bit PCI slot. CP 1623 is the modern PCI Express (PCIe x1) successor offering identical functionality and software driver compatibility for modern server mainboards.