Logging Client Workstation Names in the SIMATIC PCS 7 WinCC Operation List

In SIMATIC PCS 7 WinCC, logging the specific client computer name alongside the operator's user name in the Operation List (Bedienliste / Audit Trail) is achieved by enabling the 'Computer Name' system message block in Alarm Logging and adding the 'Computer Name' column to the WinCC AlarmControl. Once configured, every setpoint modification, manual valve command, and sequence start automatically captures both the logged-in user credentials and the physical PC station name from which the command originated.

Audit Trail Compliance and Operator Action Tracking (21 CFR Part 11)

In regulated continuous processing and batch manufacturing facilities (pharmaceutical, chemical, oil & gas), regulatory compliance standards such as FDA 21 CFR Part 11 and Good Automated Manufacturing Practice (GAMP 5) require complete auditability of operator actions.

When an operational change occurs (e.g. changing an auto/manual state or overriding a tank limit):
* The DCS must record Who performed the action (User ID / Operator Name).
* The DCS must record When it occurred (High-precision UTC timestamp).
* Crucially, in multi-client control rooms, the system must record Where the action took place (the physical PC Station Name of the OS Client console).

Enabling the Computer Name System Message Block in Alarm Logging

To activate computer name capture in the WinCC alarm recording engine:

[WinCC Explorer -> Open Alarm Logging Editor]
   │
   ├─► In Left Navigation Tree, Expand: "Message Blocks"
   │     • Select: "System Blocks"
   │
   ├─► In Right Table, Locate: "Computer Name" (Computer Name)
   │     • Double-click to open properties
   │     • Ensure: Checkbox [x] "Active" is CHECKED
   │     • Set Column Width (e.g. 15 to 20 characters)
   │
   └─► Save Alarm Logging Configuration

Activating this system block instructs the WinCC messaging service to record the network NetBIOS/DNS hostname of the client station issuing each operator command.

Configuring WinCC AlarmControl Columns in Graphics Designer

To display the Computer Name column in the runtime Operation List:
1. Open the target picture containing the operation list (e.g. @AlarmOperation.pdl or a custom audit screen) in Graphics Designer.
2. Double-click the WinCC AlarmControl to open its Configuration Dialog.
3. Navigate to the Message Lists tab.
4. Under Available message blocks, locate Computer Name.
5. Click the > button to move Computer Name into Selected message blocks.
6. Use the Up/Down buttons to position the column directly adjacent to User Name.
7. Save the picture.

Operation Message Data Structure and Parameter Mapping

The following table details message block components captured in standard PCS 7 operation lists:

Message Block NameBlock TypeData ContentAudit ValueDate / TimeSystem BlockUTC / Local TimestampVerifies precise temporal sequence of control actions.Class / TypeSystem BlockOperation / BedientextFilters operational interventions from process faults.Tag NameProcess Value BlockTechnological Tag (FIC101.SP)Identifies the specific AS technological instance commanded.User NameSystem BlockWindows / WinCC Logged UserAttaches individual human identity to the command.Computer NameSystem BlockClient Hostname (OS_CLIENT_03)Pinpoints physical control room console location.Old / New ValueProcess Value BlockNumeric change (e.g., 50.0 -> 75.0)Records the exact control parameter alteration.

Verification

To confirm that the client computer name is recorded and displayed:
1. Open WinCC Runtime on an OS Client station (e.g., CLIENT_UNIT1).
2. Log in as an operator and open any motor or valve faceplate.
3. Switch the operating mode from Auto to Manual, or adjust an analog setpoint.
4. Navigate to the Operation List (@AlarmOperation.pdl) on the operator screen.
5. Verify that a new entry appears displaying: the exact timestamp, the technological tag name, the logged-in User Name, and the Computer Name reading CLIENT_UNIT1.

Limitations and Operational Precautions

Ensure that all PC stations on the terminal bus have unique NetBIOS computer names that do not exceed 15 characters and contain no illegal punctuation or special characters. If two OS Clients share the same computer name or if DNS name resolution fails, the WinCC message engine may log blank or truncated computer names into the operation archive.

Engineer FAQ

Does logging Computer Name require a WinCC Audit license?

No. Basic Computer Name logging in the standard WinCC Operation List is a built-in feature of Alarm Logging and does not require the separate SIMATIC WinCC/Audit package. WinCC Audit is required for cryptographic checksumming and electronic signatures.

Why did the Computer Name column show blank for older entries?

The Computer Name message block captures data at the moment the message is triggered. Any operations logged prior to activating the block in Alarm Logging will have empty computer name fields.

Can Web Navigator clients log their computer names?

Yes. When commands are issued from a WinCC Web Navigator thin client, the Web client's hostname or IP address is passed to the server and recorded in the Computer Name field.

Where is the Operation List stored long-term?

Operation messages are stored inside the WinCC Alarm Logging Microsoft SQL Server database and can be archived long-term to SIMATIC Process Historian.