PCS7 Faceplate Internal Tags: WinCC Prefix-Suffix Configuration

Overview

Siemens SIMATIC PCS 7 faceplates are designed to bind to AS structure tags generated by the PCS 7 CFC/SFC compiler. When you copy a block icon and point it at a non-PCS 7 tag source (WinCC internal tags, OPC items, or a third-party PLC structure from Allen-Bradley, Modicon, etc.), the faceplate opens in runtime but every command button stays disabled, even when the operator is logged in with full administrator rights. The root cause is two-fold: (1) the prefix-suffix tag resolution inside the faceplate type cannot find the data source, and (2) the WinCC User Administrator permission fields inside the copied faceplate lose their @Level5 / @Level6 configuration, which the runtime uses to authorize operator inputs.

This reference documents the exact naming rules, the property dialogs that must be edited, the permission level wiring, and the supported Dynamic Wizard path that avoids manual editing entirely. A verification checklist and troubleshooting matrix are included at the end.

Architecture: How the Faceplate Resolves Tags

Every PCS 7 block icon carries a configurable property named Tag (German: Tagname). The value entered in this property is treated as a string prefix by the WinCC graphics runtime. Inside the faceplate, every dynamized element (status rectangle, command button, bar graph, etc.) holds a suffix property that is concatenated to the prefix at runtime.

Resolution rule:

Example: a motor faceplate element whose display property is bound to the suffix _ONOFF, inside a block icon whose Tag property is set to MYDATA, will read from the WinCC tag MYDATA_ONOFF. The faceplate does not know - and does not need to know - whether MYDATA_ONFF is a process tag, a structure tag, or a plain internal tag.

Suffix Set Used by Standard PCS 7 Motor Faceplate

The full suffix list for any given faceplate is exposed in the faceplate editor under Properties > Interface > Tag suffixes. The faceplate will resolve only the suffixes it actually references; suffixes that are not bound do not generate runtime errors.

Prerequisites

1. SIMATIC PCS 7 V7.1 SPx or later installed, with WinCC Explorer and Graphics Designer licensed.
2. WinCC User Administrator configured with at least the default authorization levels Level 5 (Process controlling) and Level 6 (Higher process controlling). The user account used to log in at runtime must be a member of an authorization group that has both levels enabled.
3. All internal tags that the faceplate will resolve must exist in the WinCC tag management before the picture is activated. If the tags live on a server, they are global; if they live on a client, the client must reference the server tag list.
4. The original (unmodified) PCS 7 block icon and faceplate available in the master data library so that properties can be diff-compared after copying.

Step-by-Step: Binding Internal Tags to a Copied Block Icon

1. Copy the original block icon in the Graphics Designer. Right-click the original icon → Copy, then paste it into the target picture. Do not copy the faceplate itself - the standard PCS 7 faceplate stays untouched.
2. Open the block icon configuration with a double-click on the icon. The Object Properties dialog opens.
3. Set the Tag property on the Properties tab to the prefix of your internal tag group, e.g. MOTOR_A1. This is the value the runtime will prepend to every suffix inside the faceplate.
4. Create the matching internal tags in WinCC: open Tag Management → Internal Tags and add every tag the faceplate will request. Use the exact prefix-suffix form, for example:

   MOTOR_A1_ONOFF        BOOL
   MOTOR_A1_START         BOOL
   MOTOR_A1_STOP          BOOL
   MOTOR_A1_FAULT         BOOL
   MOTOR_A1_AUT_ON        BOOL
   MOTOR_A1_MAN_ON        BOOL
   MOTOR_A1_PV            FLOAT
   MOTOR_A1_SP_EXT        FLOAT
   MOTOR_A1_MOP           FLOAT
   MOTOR_A1_MSG_ACK       BOOL

5. Confirm the picture activates in the WinCC Explorer (right-click → Activate). The block icon should now show the live status of the new internal tags. If all bits are still greyed, the tag names do not match the suffix set of the faceplate - jump to the Troubleshooting section.

Server vs Client Tag Placement

The PCS 7 SIMATIC area view automatically prefixes server tags with Servername:: when the picture runs on a client. This is correct behavior for a distributed system, but it can break resolution for client-local internal tags if the prefix is wrong.

Permission Levels: @Level5 and @Level6

Every standard PCS 7 faceplate contains two text fields named @Level5 and @Level6. The @ prefix is not cosmetic - it is a WinCC graphics runtime marker that tells the runtime which WinCC User Administrator authorization level is required to operate the faceplate elements bound to the field.

• @Level5 - typical inputs: start, stop, mode select. Requires authorization level Process controlling.
• @Level6 - typical inputs: setpoint write, manual override of protection blocks. Requires authorization level Higher process controlling.

If you copy a faceplate and rename the field without the @ prefix, the field becomes a static text element and the runtime can no longer gate the operator input. Result: every button is visible but disabled, regardless of who is logged in. The same failure mode appears if the user account simply does not have level 5/6 rights assigned in the WinCC User Administrator.

Verifying the Permission Wiring

1. Open the copied faceplate in the Graphics Designer.
2. Select the text field that gates the command buttons.
3. In Object Properties > Properties > Input/Output, confirm the field name is exactly @Level5 or @Level6, case sensitive.
4. In WinCC Explorer, open User Administrator, select the operator group the user belongs to, and confirm that Authorization level 5 and Authorization level 6 are checked.
5. At runtime, log out, log back in as the operator, and re-open the faceplate. The command buttons should now be enabled.

Dynamic Wizard Path (Recommended)

Manual editing of the block icon configuration is error-prone. PCS 7 ships a Dynamic Wizard that automates the binding between a block icon and a structure tag. Use this path whenever possible.

1. Select the block icon on the picture.
2. Open Dynamic Wizard > Standard Dynamics > Link a prototype to a structure.
3. In the wizard, pick the target structure (a WinCC structure tag whose member names match the suffix set of the faceplate).
4. Run the wizard. The Tag property of the block icon is populated automatically with the structure name as prefix.

The Dynamic Wizard path guarantees that the prefix is set in the same property slot the faceplate expects, and that no other property (e.g. Server prefix, Picture selection) is overwritten.

Integrating an OPC Tag Source (e.g. Allen-Bradley ControlLogix)

To drive a PCS 7 motor faceplate from a non-S7 PLC, build the same internal-tag skeleton on the WinCC side, but make each tag an OPC tag type pointing at the external DA server. The runtime resolution is identical - WinCC looks up the tag by name; it does not care whether the tag is internal, process, or OPC-sourced.

// Example: WinCC OPC tag definition for an AB ControlLogix motor
Name:        MOTOR_A1_ONOFF
Type:        OPC
OPC Server:  OPC.SimaticNet\\'\\'\\'\\'  (or RSLinx for AB)
Item:        S7:[S7_Connection_1]DB100.DBX0.0
// Or, for Allen-Bradley:
Item:        [AB_Controller]Motor_A1.Start

From the faceplate point of view, the binding is unchanged. Status readbacks come from the OPC tag's Quality code, and command writes are pushed back through the OPC item. Make sure the OPC DA server is configured for read/write on the control items (_START, _STOP, _MOP) and read-only on the status items.

Verification Checklist

• ☐ All internal tags exist in WinCC Tag Management with the exact prefix-suffix name used in the faceplate (case sensitive).
• ☐ The Tag property of the block icon contains the prefix only (no ::, no leading dot).
• ☐ On a client picture, the server prefix is either explicit or stripped depending on tag location.
• ☐ The faceplate contains the fields @Level5 and @Level6 with the @ prefix preserved.
• ☐ The runtime user belongs to a group with authorization levels 5 and 6 enabled.
• ☐ The picture has been recompiled and reactivated in WinCC Explorer after every change.
• ☐ No CS1xxx-style WinCC diagnostics appear in the DiagViewer / apdiag trace during faceplate open.

Troubleshooting Matrix

Differences in TIA Portal V20 / WinCC Unified

WinCC Unified faceplates (introduced with TIA Portal V15 and refined through V20) use a fundamentally different binding model. Instead of a string-prefix on a block icon, Unified faceplate types expose a typed interface with PLC tags, HMI tags, and local tags declared in the faceplate type itself. Local tags are scoped to the faceplate instance and can be used to pass information within the faceplate type - for example, to dynamize elements without exposing the value to the surrounding screen.

The local-tag configuration in V20 RT Unified is documented in the TIA Portal help: Configuring local tags in the faceplate type (RT Unified). The Classic PCS 7 prefix-suffix convention described above does not apply to Unified faceplates - migrating a Classic project to Unified requires recreating the bindings through the faceplate type interface editor.

Reference: PCS 7 Documentation

For the full faceplate programming model, including block icon property dialogs, suffix conventions, and the dynamic wizard catalog, refer to the PCS 7 - Programming Instruction Blocks manual installed with the PCS 7 engineering software. The same information is mirrored in the Siemens Industry Online Support portal under the manual ID A5E02709631 (subject to revision per PCS 7 version).