WinCC IEC 61850 Channel Setup: SICAM PAS, PASCC Integration Guide

Overview: IEC 61850 and WinCC Integration Paths

IEC 61850 is the international standard governing communication between Intelligent Electronic Devices (IEDs) in electrical substations and across power-utility automation. Published by IEC as the IEC 61850:2026 SER series, the standard defines a layered protocol architecture based on Manufacturing Message Specification (MMS), Sampled Values (SV), and Generic Object Oriented Substation Event (GOOSE) over multicast Ethernet, eliminating hard-wired copper between protection relays, bay controllers, and SCADA master stations. See the official IEC 61850:2026 SER catalogue entry and the IEC TC 57 IEC 61850 landing page for the authoritative scope of parts 1 through 10 (including 61850-7-4x data models and 61850-8-1 MMS mapping).

Siemens WinCC does not embed a free IEC 61850 stack. To bring substation IEDs into WinCC tags, alarms, and archives, three integration paths are field-proven on operational systems:

1. WinCC IEC 61850 Communication Channel – a native channel DLL licensed per number of polled devices (20, 50, or 256).
2. SICAM PAS with PASCC – a substation automation front-end that exposes IEC 61850 (and IEC 60870-5-101/103/104, Modbus, PROFIBUS FMS) to WinCC over OPC.
3. S7-400 IEC 61850 library – an S7 add-on that turns an S7-400 CPU into a protocol gateway in front of WinCC.

The selection is driven by IED count, existing PLC footprint, redundancy requirements (PRP/HSR), and whether buffered Reporting (RCB with Buffered Report Control Block) or unbuffered polling via GetDataObjectValue is required.

WinCC IEC 61850 Communication Channel Architecture

The WinCC IEC 61850 Channel is implemented as a Windows DLL that registers as a WinCC communication driver (channel name typically "IEC 61850 Channel"). It acts as an IEC 61850 MMS client only; the WinCC station cannot publish as an MMS server to other clients. Each channel instance reads the Substation Configuration Language (SCL) file – an .icd, .iid, or .scd exported from the IED configuration tool (e.g., DIGSI, PCM600, IET600) – and constructs a logical device model with the data objects defined in IEC 61850-7-4.

Communication parameters exposed in the channel configuration include:

• IP address / subnet mask of the target IED (each device is one channel unit).
• MMS local port (default 102) and remote TSAP/APPID mapping for GOOSE.
• Polling interval for unbuffered data (typical 1 s – 10 s).
• Report Control Block (RCB) activation for buffered event-driven reports.
• Dataset definitions referenced from the SCD.

Licensing Tiers and Device Capacity

The WinCC IEC 61850 Channel is licensed per channel instance count, not per tag. Three discrete tiers exist:

Each tier installs the same DLL set; the runtime check is enforced by the license dongle or softkey (Automation License Manager). Adding an S7-400 station with the IEC 61850 add-on library does not consume an IEC 61850 Channel license for the WinCC side because data is delivered over native S7 MPI/Profibus/Industrial Ethernet to WinCC, not over MMS.

SICAM PAS with PASCC: OPC Tunneling Path

SICAM PAS (Power Automation System) is Siemens' substation automation front-end used in transmission and large distribution substations. It supports IEC 61850, IEC 60870-5-101, -103, -104, Modbus, and PROFIBUS FMS as parallel protocols. PAS exposes its internal point database as OPC DA / OPC HDA / OPC AE. The PAS-to-WinCC bridge is sold as a separate add-on called PASCC (PAS Connectivity Component), delivered as a set of DLLs that register as an OPC DA 2.0 / 3.0 server on the WinCC station and as a PAS internal task on the PAS station.

PASCC topology:

IEDs (MMS)  -->  SICAM PAS Station  --(LAN)-->  OPC tunnel  -->  WinCC OPC DA Client
       (IEC 61850-8-1)              (PASCC DLL on WinCC side)

Why choose PASCC over the native channel?

• PAS handles redundant LAN coupling (PRP, HSR, RSTP) and dual IEC 61850 station addressing natively, offloading complexity from WinCC.
• PAS provides protocol conversion (IEC 61850 <-> DNP3, IEC 60870-5-104, Modbus) for downstream non-WinCC masters.
• PAS adds an event/time-stamping layer aligned with IEC 61850-7-3 quality flags, which WinCC displays directly.
• PASCC upgrade can be purchased standalone – the DLLs are licensed to communicate with PAS without re-buying a full WinCC license.

S7-400 IEC 61850 Library as Protocol Gateway

Where an S7-400 is already present (common in power plants and brownfield substations), the S7-400 IEC 61850 add-on library converts the CPU into a protocol converter. The library is loaded into a CP 443-1 communications processor or a CPU with Ethernet PN interface and uses a SCL-imported IED list to map logical nodes onto DB tags. The S7-400 then writes those tags to WinCC over S7 Communication (PUT/GET or S7 Connection).

This topology is preferred when:

• Existing S7-400 logic must interlock against measured values (e.g., breaker control interlocks).
• Latency between IED and PLC must be sub-second and cannot tolerate a PC-based OPC hop.
• The customer already pays for S7-400 redundancy and wants a single point of failover.

Third-Party OPC Server Option

Independent of Siemens offerings, several third-party IEC 61850 OPC DA / UA servers (Kepware, Matrikon, SystemCORP, Softing) ship IEC 61850 client stacks and expose the data model to WinCC through the standard OPC channel. This path is selected when:

• WinCC is required to remain on a Siemens-license-only basis but the IEC 61850 channel licensing tiers (20/50/256) do not fit the project.
• OPC UA is preferred over OPC DA for the WinCC side, and the third-party server supports IEC 61850 to OPC UA bridging.
• Mixing non-Siemens IEDs (ABB REL, GE UR, SEL-487B) whose SCL files require non-Siemens feature flags that the WinCC native channel rejects.

The WinCC OPC channel is bundled (no separate license) and handles the connection to any compliant OPC DA server. Security architecture, certificate handling, and SCL import validation become the integrator's responsibility.

IEC 61850 Protocol Stack Reference

WinCC never receives GOOSE directly because GOOSE is Layer-2 multicast (Ethertype 0x88B8) and is not forwarded by routers. WinCC consumes MMS over TCP/102 only.

Configuration Procedure: WinCC IEC 61850 Channel

Prerequisites

• WinCC 7.x or TIA Portal WinCC Professional with the IEC 61850 Channel option package installed.
• Automation License Manager showing the correct 20/50/256 device softkey.
• SCD or ICD file exported from the IED engineering tool.
• PC network adapter on the same subnet/VLAN as the IEDs; Layer-3 reachability to each IED's MMS port 102.

Step-by-Step

1. In WinCC Explorer, right-click Tag Management and add a new connection. Driver selection: IEC61850 Channel.
2. Open the IEC 61850 Channel properties. Add a channel unit per physical or logical IED. Enter the IED's IP_ADDRESS and the Logical Device name exactly as it appears in the SCD (case-sensitive, e.g., PROT_IED1LD0).
3. For each channel unit, browse the imported SCD to select Logical Nodes and Data Objects. The channel exposes them as internal WinCC tags with the LN/DO path encoded, e.g., PROT_IED1LD0/PROT/CILO1/Pos/stVal.
4. Configure update mode per tag: On demand (polling) for measurements using GetDataObjectValue, or On change (RCB) to subscribe to buffered/unbuffered reports.
5. Set quality code propagation: WinCC displays Good, Invalid, Reserved, Questionable as defined in IEC 61850-7-3.
6. Save, activate WinCC, and observe the channel diagnostics in the WinCC Channel Diagnosis tool. Look for "MMS association established" per device.

Verification

• Force a tag change in the IED test set; confirm WinCC archive receives the value within one polling interval (or within one RCB report for event-driven tags).
• Disconnect the IED's network cable; confirm WinCC tags show quality Bad and an alarm is raised.
• Check WinCC channel log for MMS error codes (e.g., 0x0001 access violation, 0x0002 instance not available).

Configuration Procedure: SICAM PAS with PASCC

Prerequisites

• SICAM PAS V8.x or later on the front-end station, licensed for IEC 61850 with sufficient device slots.
• PASCC upgrade license on the WinCC station (covers OPC DLL registration).
• PAS user account with rights to expose points to OPC.
• Network route from PAS station to WinCC OPC port (typically DCOM-allocated, use OPCEnum to confirm).

Step-by-Step

1. In PAS Studio, import the substation SCD and assign each IED's MMS access point to a PAS device.
2. Map Logical Node data objects to PAS internal points. Define a point list for the signals WinCC must read.
3. Activate the OPC DA server task in PAS; verify OPCEnum on the PAS station lists SICAM.PAS.1.
4. On the WinCC station, install the PASCC DLLs (these are the OPC proxy side) and restart the WinCC OPC service.
5. In WinCC Explorer, add an OPC connection and browse the PAS server. Import the points exposed by PAS.
6. Configure WinCC alarm and archive tags to map onto the OPC tag namespace.

Verification

• Use an OPC DA test client (e.g., OPC Quick Client) on the WinCC station to confirm read/write access to PAS points before binding them to WinCC tags.
• Verify timestamps originate from PAS (and therefore reflect IEC 61850 quality + time-stamp) rather than from the WinCC scan clock.
• For redundant PAS stations, confirm the WinCC OPC channel fails over within the configured timeout.

Buffered vs. Unbuffered Reports

IEC 61850-7-2 defines two Report Control Block types:

If the WinCC PC loses power, a buffered RCB will resend the queued events when the MMS association re-establishes. Unbuffered polling (GetDataObjectValue) is stateless and simply resumes on next poll. For protection-relevant tags (e.g., trip commands, breaker position), always bind to a buffered RCB with integrity period of 30 s or less.

Troubleshooting Matrix

Standards and Compliance Notes

Cross-reference the IEC 61850 series published by IEC; the current consolidated edition is IEC 61850:2026 SER, which includes a 15% discount on the full catalogue. Part 8-1 (MMS mapping) and Part 7-2 (ACSI) are the parts most directly relevant to a WinCC integrator. The IEC TC 57 IEC 61850 home page lists ongoing amendments and corrigenda; always build against the edition named in the IED's PICS (Protocol Implementation Conformance Statement) to avoid revision drift.

For substation projects, also verify compliance with regional utility profiles (e.g., IEC 61850-90-5 for WAN routing, IEEE 1613 for environmental hardening) before selecting the channel topology. The IEC standard documents are reference texts to verify against – they do not by themselves guarantee interoperability, which is established through the IED's conformance test certificates.

FAQ