Configuring PCS 7 Redundant AS with IPC547C ES/OS and CP1623

Overview

This reference documents the sizing, component selection, and licensing required to build a SIMATIC PCS 7 V7.1 engineering and operator system that is connected to a redundant AS-410H automation station. The architecture uses two CPU 412-3H controllers with F-Runtime license on the AS side, and a SIMATIC PCS 7 Industrial Workstation IPC547C ES/OS Single Station IE (MLFB 6ES7660-0BC31-2AA0) on the operator side. The "IE" suffix on the workstation bundle denotes that the CP1623 communication processor is integrated, but it does not cover the additional S7-REDCONNECT software that is required to talk to the fault-tolerant AS over the H-station redundancy protocol.

Engineers new to PCS 7 frequently under-estimate the licensing that surrounds a redundant AS connection. The hardware bundle typically ships with the operating system, the PCS 7 engineering and runtime media, and the CP1623 card, but the S7-REDCONNECT runtime license and the Process Object (PO) license must be procured separately. This article resolves those decisions against Siemens' official IPC547C bundle documentation.

AS-410H System Architecture

The redundant AS is built on the SIMATIC S7-400H platform. Each H-station contains two CPU 412-3H controllers that execute the same user program synchronously over fiber-optic sync links (sync modules and sync cables). The two halves of the H-station present themselves to the ES/OS as a single logical address, which is the reason a special connectivity software (S7-REDCONNECT) is required on the operator side.

For a fault-tolerant PCS 7 deployment, the basic AS bill of materials is:

• 2 x CPU 412-3H (MLFB 6ES7 412-3HJ14-0AB0 family)
• 2 x sync module (fiber-optic) and 2 x sync cable
• 2 x UR2 / UR2-H rack (or one combined rack with redundant backplane, depending on the configuration)
• 2 x PS 405 (or PS 407) power supply modules
• F-Runtime license (MLFB 6ES7656-8AB33-2BD0) for the safety functions enabled by the CPU 412-3H
• I/O on PROFIBUS or PROFINET with the appropriate Y-Link or redundant PROFINET topology

The F-Runtime license is loaded once per AS station and is independent of the ES/OS. It enables the CPU 412-3H to run the S7 F-systems (Distributed Safety / Failsafe) library blocks used in PCS 7 safety programs.

Hardware Selection: AS and ES/OS Bundles

The following table summarizes the part numbers referenced in this architecture and the function each one plays. The IPC547C ES/OS bundle MLFB 6ES7660-0BC31-2AA0 is the V7.1 variant of the "Industrial Workstation ES/OS Single Station IE" bundle.

Engineers should treat the two IPC547C MLFBs above as functionally equivalent for the purposes of the connectivity question; the relevant differences are the bundled PCS 7 version (V6.1 SP4 vs V7.1) and the operating system pre-installed. The connectivity topology described in this article is the same for both bundles.

CP1623: One Card or Two?

The "IE" suffix on the IPC547C bundle means that the workstation is delivered with one CP1623 communication processor already installed and licensed at the bundle level. The CP1623 is a PCI-Express card that implements a Layer-2 Industrial Ethernet interface and is the recommended partner for S7-REDCONNECT because it supports the ISO-on-TCP and ISO protocols at the highest determinism level.

For a single ES/OS connecting to one redundant AS, one CP1623 is sufficient. The CP1623 sits on the same plant bus (Industrial Ethernet, e.g. a SCALANCE X-200 / X-300 ring) as both CPUs of the H-station, and S7-REDCONNECT presents the H-station's redundant pair as a single logical S7 connection. There is no redundancy on the ES/OS side unless a second ES/OS is added (which is a separate workstation bundle, not a second CP1623 in the same chassis).

You only need a second CP1623 in the same IPC547C if one of the following is true:

• You are building a fault-tolerant OS pair on the same single-station bundle (a soft-redundant OS), which is not the configuration offered by the "Single Station" MLFB.
• You are splitting the engineering network (terminal bus) from the plant bus and want to keep both physical networks inside the same IPC for the engineering client. In that case, the second CP1623 acts as the terminal-bus interface; the first CP1623 still terminates the plant bus to the redundant AS.
• You are stacking two redundant AS connections in a multi-project environment and want to bind each AS to a dedicated CP1623 for traffic isolation.

For a first PCS 7 project with one AS-410H and one ES/OS, order the bundle as quoted. Adding a redundant CP1623 in the same chassis is an advanced topology and should be confirmed against the project network design before procurement.

S7-REDCONNECT Software License

S7-REDCONNECT (sold as SOFTNET-S7-REDCONNECT, MLFB 6GK1716-0HB70-3AA0) is the runtime add-on that lets a WinCC / PCS 7 OS client maintain a stable S7 connection to one of the two CPUs in an H-station even if the active CPU fails over to its redundant partner. Without S7-REDCONNECT, WinCC can only be configured to a single CPU address; the moment the H-system fails over, the OS loses its connection and must be re-instantiated by hand.

Each ES/OS that connects to a redundant AS requires exactly one S7-REDCONNECT license. If the project has one ES/OS (this case), order one license of 6GK1716-0HB70-3AA0. If the project has two operator stations, order two. The license is independent of the number of AS connections that one ES/OS opens (a single ES/OS can monitor many ASes, but it needs only one REDCONNECT license per ES/OS as long as the OS is binding to the H-station through S7-REDCONNECT).

S7-REDCONNECT is installed alongside WinCC / PCS 7 OS on the IPC547C. After installation, configure the connection in the PCS 7 ES project under "WinCC Explorer > OS > Connection > Redundant AS" and point the H-station's CP443-1 (the IE interface on the S7-400H) to the CP1623 IP address. The CP1623 must be set to "Promiscuous mode = on" and "Connection mode = S7-REDCONNECT" in the SIMATIC NET configuration tool.

Process Object (PO) License Sizing

Pre-installed PCS 7.1 on the IPC547C does not include the PCS 7 process object (PO) license. The OS counts every measured, controlled, monitored and operated variable as a PO, and the engineering project must be sized against one of the standard PO counts (PO 250, PO 1k, PO 2k, PO 3k, PO 5k, and higher tiers for very large plants). For a first project, the AS/OS PO 250 floating license (MLFB 6ES7658-5AA17-0YA5) is the smallest tier.

PO 250 is acceptable only if the I&E scope totals 250 or fewer process objects. As soon as the project crosses 250 POs, the OS will operate in a "limited" mode where excess objects can be monitored but not controlled (Operate and Control are throttled at 250; monitoring continues to higher numbers but is not officially supported). A second PO 250 license can be added; the system will then run with 500 POs. Higher tiers (1k, 2k, 3k, 5k) are PO "count upgrades" that allow scaling without re-installing the OS.

To count POs, sum the number of:

• Analog and digital measurements (AI / DI blocks)
• Analog and digital control blocks (PID, motors, valves, drives)
• Operator-control-relevant alarm and message blocks
• Driver and channel blocks that the CFC/OS counts as POs

Use the PCS 7 Engineering tool's PO report (Project > Reports > PO Report) before ordering the license. Do not guess. If the PO count is close to the 250 boundary, order the next tier instead of the smallest one.

IPC547C Bundle Variants and Power Supply

Per the official Siemens bundle documentation (SIMATIC PCS 7 V7.0 IPC547C bundle datasheet and the SIMATIC PCS 7 V6.1 SP4 IPC547C bundle datasheet), the IPC547C industrial PC is offered with an optional redundant power supply. The redundant PSU option is a build-to-order configuration and can only be ordered together with the matching PCS 7 ES/OS bundle. It is not sold as a stand-alone field upgrade.

Two bundle families are documented in the Siemens datasheets:

• Single Station (ES/OS): one engineering seat and one operator seat on one IPC547C. This is the MLFB 6ES7660-0BC31-2AA0 quoted in the original question. The "IE" variant includes the CP1623.
• Server / Client variants: separate OS server and OS client bundles for multi-station systems. These are not relevant for a single-station first project, but should be considered for scaling beyond the first OS.

The redundant power supply variant is recommended for new deployments where the IPC547C is installed in a cabinet that already has two 24 V or 110/220 V AC feeds. It is not required for the redundant AS to function; it only protects the ES/OS from a single power-feed failure on the operator side.

Configuration Procedure

1. Verify the AS-410H is assembled and powered. Insert the two CPU 412-3H in slots 3 of each UR2-H rack, install the sync modules in the IF1 / IF2 slots of each CPU, and connect the two sync cables. Power on both racks.
2. Install the IPC547C ES/OS bundle. Mount the IPC547C in the cabinet, install the redundant PSU wiring if the option is ordered, and power on. Boot the pre-installed Windows / PCS 7.1 image.
3. Configure the CP1623 IP address. Open "SIMATIC NET Configuration > CP1623" and assign an IP address on the plant bus subnet. The two CPU 412-3H CP443-1 modules must be on the same subnet.
4. Install the S7-REDCONNECT license. Run the S7-REDCONNECT setup, then transfer the license key from the license USB stick to the local license server on the IPC547C using the Automation License Manager.
5. Configure the redundant AS connection in WinCC Explorer. In the OS project, edit the S7 connection and set the target to "S7-REDCONNECT", pointing at the H-station's CP443-1 IP address. Compile and download the OS server / single station runtime.
6. Load the AS project with the F-Runtime license. In SIMATIC Manager / PCS 7 ES, open the S7 program on the H-station, select "Target system > Load to target", and confirm the F-Runtime license prompt.
7. Run a failover test. Pull the power on CPU 0 of the H-station. The OS should remain in run mode; only the connection path changes. Restore power, repeat for CPU 1.

Verification and Acceptance

After commissioning, the following checks confirm that the configuration matches the design:

• Plant bus connectivity: ping both CP443-1 IP addresses from the IPC547C command line. Both must respond before the OS is started.
• S7-REDCONNECT status: in WinCC Explorer, open the OS connection diagnostics. The connection state must read "Connected to CPU0/1 (H-station)" rather than just "Connected to CPU x".
• Failover time: a healthy H-station fails over within 100 ms to 300 ms. Verify that the OS does not display any connection-loss event during failover by checking the WinCC alarm log after a controlled CPU power-down.
• PO count: the OS server should report "POs in use: N / 250" or higher. If the counter exceeds the licensed PO count, the OS will run in restricted mode. Fix the license or the I&E scope before acceptance.
• F-Runtime status: in the S7 program, the F-runtime signature must be valid. Open "Safety > F-Runtime signature" and confirm the displayed signature matches the one captured at the start of the project.

Troubleshooting Matrix

Component Cross-Reference

The bundle MLFBs change between PCS 7 releases. For a V7.1 deployment, the 6ES7660-0BC31-2AA0 bundle is correct. Engineers maintaining older V6.1 SP4 systems should reference 6ES7660-0AF33-2BA2. The connectivity decisions (one CP1623, one REDCONNECT license per ES/OS) are the same across both bundles because the CP1623 and the H-station topology have not changed between V6.1 SP4 and V7.1.

The official Siemens bundle datasheets for the IPC547C family are the source of truth for the available bundle options and the redundant power supply constraint. Always cross-check the MLFB you order against the matching release of those PDFs before placing the order.