Demystifying PG Mode Versus Configured Mode in SIMATIC PCS 7 PC Stations

In SIMATIC PCS 7, the distinction between PG Mode and Configured Mode governs how a computer's network interface cards (NICs) communicate with industrial automation systems. In PG Mode (the default setting for temporary laptops and programming devices), the PC acts as a basic programming terminal using direct access points (such as S7ONLINE -> TCP/IP) without virtual rack components. In Configured Mode, the computer operates as a formal SIMATIC PC Station managed by the Station Configuration Editor (Station Configurator); the virtual rack hosts software applications (WinCC Application, OpenPCS 7, Batch) and communications processors (CP 1623, IE General) linked to NetPro. In PCS 7 architectures: the Engineering Station (ES) and OS Servers must be in Configured Mode, OS Clients operate in Configured Mode (or PG mode depending on architecture), and dedicated Historian/OpenPCS 7 servers require Configured Mode.

Executive Summary

Proper configuration of communications hardware in SIMATIC PCS 7 requires understanding how Siemens software maps physical network adapters to virtual software containers. Engineers frequently struggle with the Station Configuration Editor and 'Set PG/PC Interface', unsure whether a workstation should run in 'PG Mode' or 'Configured Mode'. Selecting the incorrect mode prevents downloading network connection routing tables, disables fault-tolerant S7-REDCONNECT protocols, and blocks WinCC Runtime from establishing named connections to automation controllers. Clear demarcation of station roles ensures stable, multi-channel DCS communication across the Plant Bus and Terminal Bus.

Architecture and Fundamental Mechanics

The architectural framework of SIMATIC NET communication modes operates through distinct software layers:

PG Mode (Programming Device Mode):
* In PG Mode, the physical network adapter operates as an unmanaged communications interface.
* Applications bind directly to the hardware card using the Set PG/PC Interface utility (e.g., assigning S7ONLINE to TCP/IP(Auto) -> Realtek PCIe).
* The PC cannot host a virtual rack in Station Configuration Editor, cannot participate in NetPro named S7 connections, and cannot manage multiple concurrent protocol endpoints.
* PG Mode is appropriate for mobile maintenance laptops, standalone STEP 7 micro-systems, and temporary commissioning nodes.
Configured Mode (SIMATIC PC Station Mode):
* In Configured Mode, the computer is modeled in SIMATIC Manager as a formal SIMATIC PC Station.
* The Station Configuration Editor establishes a virtual backplane rack with slots 1 through 32.
* Virtual software components occupy defined slots: WinCC Appl. in Slot 1, Application in Slot 2, CP 1623 or IE General in Slot 3, etc.
* The operating system loads compiled configuration files (.xdb) or receives direct network downloads (PLC > Download) from NetPro.
* This mode enables Named S7 Connections, bidirectional routing across Plant and Terminal buses, and S7-REDCONNECT high-availability redundancy.
Application by Station Type in PCS 7:
* Engineering Station (ES): Configured Mode! Must host the local WinCC Application and network CP to compile and test OS runtimes and route AS-OS downloads.
* OS Server (Single / Redundant): Strictly Configured Mode! Requires WinCC Appl. and CP 1623 / IE General in virtual rack to maintain continuous named S7 connections to AS controllers.
* OS Client: Configured Mode (with WinCC Appl. Client or standard configuration) when managed from SIMATIC Manager; communicates over Terminal Bus.
* Process Historian / OpenPCS 7: Configured Mode if hosting SIMATIC NET OPC or Historian CAS interfaces.

Step-by-Step Implementation Procedure

Follow these procedures to set up and verify Configured Mode on a PCS 7 PC Station:

Configure SIMATIC PC Station in SIMATIC Manager:
* In SIMATIC Manager Component View, insert a SIMATIC PC Station.
* Match the station object name exactly to the physical Windows Computer Name (case-sensitive, e.g., OS_SRV_01).
* Open HW Config for the PC Station.
* Insert components into virtual slots (e.g., Slot 1: WinCC Appl., Slot 2: IE General or CP 1623).
* Connect the network adapter to the Plant Bus subnet with its static IP address.
* Save and compile HW Config.
Configure Station Configuration Editor on the Physical PC:
* On the target station, locate the Station Configuration Editor icon in the Windows taskbar system tray.
* Verify that the virtual rack matches HW Config:
- Slot 1: Add WinCC Application.
- Slot 2: Add IE General (select the physical Ethernet card).
- Ensure the Station Name in Station Configuration Editor matches the Windows Computer Name.
Download Station Configuration from SIMATIC Manager:
* On the Engineering Station, open HW Config for the PC Station.
* Click PLC > Download.
* In the target selection dialog, enter the IP address of the target PC.
* The station configuration and NetPro connections are downloaded into the target PC's virtual rack.
Verify Station Configuration Editor Status:
* On the target PC, inspect the Station Configuration Editor.
* Verify that the status column for each component displays a clean pencil/ruler icon with OK (green checkmark or running state).
* The station is now locked in Configured Mode.
Verify Named Connections in NetPro:
* Open NetPro on the ES.
* Highlight the WinCC Application inside the PC Station.
* Verify that the S7 named connection to the AS controller displays active green status.

Verification

In Station Configuration Editor on the target PC, confirm that the station name displays a solid white icon and that all components report 'Configured and Running'. Open WinCC Explorer and activate Runtime; open the 'Channel Diagnosis' tool and verify that the 'Named Connections' channel reports 'Ready' with green checkmarks connecting to all AS controllers.

Limitations and Operational Precautions

The Station Name in the Station Configuration Editor, the Windows Computer Name, and the PC Station object name in SIMATIC Manager must match exactly, including character casing; any discrepancy causes station manager download index errors (Index 125). Never switch an operating OS Server back to PG Mode.

Engineer FAQ

What happens if an OS Server is left in PG Mode?

WinCC Runtime will fail to establish named S7 connections to AS controllers, resulting in disconnected process graphics and blank faceplates.

Can a laptop ES be switched between PG Mode and Configured Mode?

Yes. A commissioning engineer can switch an adapter between PG Mode (for ad-hoc PLC maintenance) and Configured Mode (for formal multiproject engineering).

Does an OS Client require CP 1623 in its virtual rack?

No. OS Clients communicate with OS Servers over the Terminal Bus using commercial standard Ethernet cards (IE General) or standard Windows networking.