Configuring Button Visibility and Operator Control on APL OpDi03 Faceplates in PCS 7

In SIMATIC PCS 7 Advanced Process Library (APL), the digital operator block OpDi03 (FB1865) displays three control buttons by default. Leaving the third input disconnected does not automatically hide its button on the faceplate. To suppress or disable the third button, configure the block's OS permission word (OS_Perm.Bit2 = 0) to lock operator access to Button 3, clear the button text label (Text3 = '') in CFC, or select the dedicated two-state operator block OpDi01/OpDi02 instead of modifying standardized faceplate scripts.

Architecture of Digital Operator Blocks in PCS 7 APL

In SIMATIC PCS 7 Advanced Process Library (APL), operator input blocks—such as OpDi01 (FB1866) and OpDi03 (FB1865)—allow operators to write digital values, mode selections, or operating setpoints directly into automation logic from WinCC faceplates.

The block OpDi03 (Operator Digital 3 Values) provides three independent operator command buttons (Button 1, Button 2, Button 3) which set corresponding digital outputs (Out1, Out2, Out3).

Engineers frequently face a situation where a technological unit requires only two operating states (e.g., Forward and Reverse, without a third state), but they instantiate OpDi03. When the engineer leaves input channel 3 disconnected in CFC, the WinCC faceplate (@pg_OpDi03.pdl) continues to display the third button row.

This occurs because standard APL faceplates are generic system templates:
* The faceplate evaluates the block structure and renders all three buttons unless specific parameter attributes or permissions suppress them.
* Disconnecting an input in CFC only sets the internal value to 0; it does not notify the graphics runtime to collapse the layout grid.

APL Operator Block Selection and Parameter Matrix

Compare operator block functionality across the Advanced Process Library:

Block TypeBlock NumberNumber of Operator OutputsFaceplate RepresentationRecommended Technological ApplicationOpDi01FB18661 digital output (Out)Single button or toggle switchSimple On/Off commands, Enable/Disable togglesOpDi03 (Full)FB18653 digital outputs (Out1..3)3 discrete pushbuttons3-position selector switches (e.g., Low / Med / High)OpDi03 (Suppressed 3rd)FB18652 active outputs (Out1..2)Button 3 locked / blanked via OS_PermDual-direction commands with interlocked 3rd channelOpAnLFB18671 analog output (SP_Out)Analog setpoint slider and input fieldTemperature, pressure, or flow setpoint entry

Engineering notice: Selecting the block that matches exact process requirements avoids faceplate customization.

Configuring OS_Perm and Button Text Suppression in CFC

To restrict access and blank the third button row on OpDi03:

Disable Operator Permission on Channel 3 (OS_Perm):
* Open the CFC chart containing the OpDi03 block.
* Locate the parameter OS_Perm (DWORD).
* Open the parameter bitmask:
- Bit 0: Operator can set value 1 (Button 1).
- Bit 1: Operator can set value 2 (Button 2).
- Bit 2: Operator can set value 3 (Button 3).
- Set OS_Perm.Bit2 = 0.
- When OS_Perm.Bit2 = 0, the runtime faceplate permanently disables Button 3, rendering it grayed out with an unauthorized lock symbol.
Clear the Text Label for Channel 3:
* In CFC, open the block properties of OpDi03.
* Switch to the Inputs/Outputs tab.
* Locate parameter Text3 (or SetOp03).
* Delete any descriptive string, leaving the field empty ('').
Configure Link or Operator Control (LiOp):
* If parameter LiOp = 1, control is transferred exclusively to upstream CFC logic, locking out all faceplate buttons. Ensure LiOp = 0 for operator manual control.

Alternative Architectural Approach: Selecting Dedicated APL Operator Blocks

If the process requires strictly two operating buttons:
1. Replace with Dedicated Logic:
* Instead of utilizing OpDi03 with a suppressed third channel, replace it with OpDi01 paired with an inverter, or use custom selection logic.
* OpDi01 provides a clean faceplate with a single toggle button (State 0 vs. State 1), preventing operator confusion and minimizing screen clutter.
2. Compile and Update OS:
* After replacing or modifying block parameters, execute Compile OS (Scope: Changes only) to update WinCC structure tags and text libraries.

Verification

Verify button behavior in WinCC Runtime:
1. Open the process screen and click the OpDi03 block icon to launch @pg_OpDi03.pdl.
2. Confirm that Button 1 and Button 2 display active text labels and respond to operator mouse clicks.
3. Confirm that Button 3 is completely disabled, grayed out with a padlock symbol, and displays no text.
4. Attempt to click Button 3: Confirm that the system rejects the input and logs no unauthorized commands.

Limitations and Operational Precautions

Never modify @pg_OpDi03.pdl in Graphics Designer to physically delete the third button control; modifying standard APL faceplates causes them to be overwritten during subsequent OS-Project Editor runs.
In automated batch processes, ensure LiOp is properly interlocked with recipe phase logic to prevent operators from overriding dosing commands manually.
Check that user authorization levels (Level 5 or Level 6) are assigned correctly in WinCC User Administrator.

Engineer FAQ

Can the third button row be completely hidden rather than grayed out?

Standard APL faceplates do not collapse the row dynamically; they disable it via OS_Perm. To completely collapse the row, you must create a project-specific faceplate template (e.g., '@pg_OpDi02_Custom.pdl').