Resolving WinCC Comfort V13 Multiple-Bit Animation Display Issues

Resolving WinCC Comfort V13 Multiple-Bit Animation Display Issues

When configuring Display/Appearance animations on a Siemens TP1900 Comfort panel running WinCC Comfort V13 (TIA Portal V13), engineers frequently encounter a behavior where a status rectangle returns to its initial gray fill whenever more than one bit of the source tag is set simultaneously. This reference documents the underlying cause, three field-proven remediation paths, and the configuration steps required to restore correct multi-bit visualization without redesigning the entire HMI screen.

1. Problem Statement

A status word is bound to a 16-bit integer HMI tag where each bit carries an independent meaning:

The engineer places a rectangle on the screen, opens Properties → Animations, adds a Display/Appearance animation of trigger type Multiple bits, and configures three table rows that map bits 0, 1, and 2 to the three colors above. When only one bit is set at runtime, the rectangle adopts the configured color. When any combination of two or three bits is set (e.g., manual mode + error), the rectangle snaps back to the design-time initial (gray) fill. There is no compiler warning, no runtime alarm, and the tag value remains unchanged in the diagnostics view.

2. Affected Versions and Components

The TP1900 Comfort is a 19-inch widescreen panel from the Comfort family with WinCC RT Advanced as the runtime. The animation lookup engine is shared across all Comfort panels; only the display size and number of available tags differ.

3. Root Cause Analysis

The Multiple bits animation type is implemented as an exact-match state-table lookup. At runtime, the engine reads the current value of the source tag and scans the configured table rows from top to bottom, applying the appearance associated with the first row whose value equals the tag value. If no row matches exactly, the object falls back to its static design-time initial appearance—the gray fill configured at edit time. The table is therefore a state-table, not a priority encoder.

For a three-bit status word the reachable values are 0..7:

The runtime only finds an exact match in the three single-bit rows. Any multi-bit combination is "not defined" from the engine's perspective, so it renders the design-time initial state. This behavior is intentional, not a defect, and exists to preserve the deterministic lookup semantics introduced with the first TIA Portal generation. The general procedure to attach a Display/Appearance animation is documented in the official WinCC Advanced V13.0 SP1 help system (Siemens support entry ID 109091876).

4. Solution A — Enable Bit Selection for Appearance

WinCC V13 SP1 UPD3 PRO introduces a project-level runtime switch that replaces the exact-match lookup with a least-significant-bit (LSB) priority encoder. The runtime tooltip reads verbatim:

Specifies that bit selection is used for appearance analysis on this HMI device. If enabled, in each case the color and the flashing that has been configured for a set bit with the least significance is shown. If disabled, the color and the flashing that has been configured for a set bit only is shown. This setting is deactivated by default to maintain downward compatibility.

With the same three-row table described in section 1, enabling the option yields:

4.1 Configuration Path

1. In the TIA Portal project tree, select the HMI device (TP1900 Comfort).
2. Open Runtime settings from the inspector window or right-click context menu.
3. Navigate to the Screens category in the left pane.
4. Tick the Bit selection for appearance checkbox.
5. Recompile the HMI project (full, not incremental) so the new runtime flag is embedded in the image.
6. Download to the panel and verify with a known multi-bit tag value (see section 8).

5. Solution B — Define Value Combinations Instead of Bits

If the bit priorities do not map to LSB-wins semantics, replace the Multiple bits animation with an animation that lists every reachable combination as an explicit row. For three independent bits you must enumerate 2³ = 8 rows; the maximum number of rows supported in a single animation table is 50, so up to a five-bit status word (32 rows) remains tractable inside a single table.

This approach scales linearly with the bit count and remains fully deterministic. It is the recommended pattern when the application logic must reach every combination and every combination carries distinct meaning. The drawback is that any change in the bit semantics requires editing the table; row count growth can also reach the 50-row ceiling for six or more bits, forcing a switch to Solution C.

5.1 Configuration Path

1. Select the rectangle, open Properties → Animations.
2. Remove the existing Display/Appearance animation of type Multiple bits.
3. Add a new Display/Appearance animation.
4. Change the trigger type from Multiple bits to Value range (or Bit in some TIA Portal builds—check the inspector dropdown).
5. Bind the same status-word HMI tag.
6. Add a row for every combination listed in the table above and assign the appearance for each row.
7. Compile, download, and verify per section 8.

6. Solution C — Layered Visibility Animation

When the operator must simultaneously see more than one state (for example, a permanent color for the operating mode plus a blinking overlay for faults), split the visualization into N stacked rectangles—one per logical state—and use the Visibility animation instead of Appearance. Each rectangle is bound to a single bit and rendered only when that bit is set. Z-order determines the visual priority: place the most critical state at the top of the layer stack so its blinking animation is not occluded.

6.1 Configuration Path

1. Stack three identical rectangles at the same screen coordinates. In the WinCC Comfort layer palette, drag them so that the lowest-priority bit is at the bottom and the highest-priority bit is on top.
2. Set the initial Visibility property of each rectangle to Hidden.
3. For each rectangle, open Properties → Animations and add a Visibility animation.
4. Select trigger type Bit and bind the appropriate bit (0, 1, or 2) of the status word.
5. Configure the blink on the topmost rectangle by adding a separate Flashing property animation, or use the built-in Flashing property of the rectangle's background color.

The layered approach is the most flexible: it scales beyond the 50-row table limit, supports arbitrary overlays, and lets each state keep its own animation timing. The trade-off is increased screen-object count and a slightly larger RT memory footprint; on the TP1900 Comfort this rarely matters because the panel ships with ample RAM for hundreds of layered objects.

7. Choosing the Right Solution

8. Tag Configuration Prerequisites

Before any animation will work reliably, the HMI tag must satisfy the following requirements:

• Data type: Use Int, UInt, or Word as the HMI tag data type. Avoid Bool—WinCC will not interpret bit patterns on a single boolean.
• Length: The tag must be at least 16 bits wide to hold the standard status word. WinCC allows 8-bit, 16-bit, and 32-bit unsigned integers; 16-bit is the canonical choice for status words because it matches the S7 WORD PLC type.
• Acquisition: Set acquisition mode to Cyclic continuous with a poll interval of 1 s for status words that change rarely; 500 ms for fast-changing alarms. Do not set acquisition to On demand for animations; WinCC only evaluates animations when the source tag updates.
• PLC connection: The HMI tag must be tied to a valid PLC tag or DB bit-pattern source. Tag consistency errors will silently disable the animation and the rectangle will remain on its initial fill.

9. Verification Procedure

1. Compile the HMI project fully (not incremental) to force regeneration of the animation tables and runtime flags.
2. Download to the TP1900 Comfort panel using either Ethernet (S7ONLINE access point) or USB/PROFINET.
3. Open the WinCC Runtime Simulator via Tools → Start Runtime, or force values directly on the connected PLC with PLCSIM.
4. Force the status word to each of the test values 0, 1, 2, 3, 4, 5, 6, 7 and confirm visually that each value produces the expected rectangle appearance.
5. Open Project → Compiler output and confirm there are no warnings tagged with the animation reference.
6. Power-cycle the panel and repeat the test to confirm the configuration survives a cold start.
7. If the project uses Solution A, also verify that switching from a multi-bit value (e.g., 3) to a single-bit value (e.g., 1) updates the rectangle within one acquisition cycle.

10. Performance Considerations on TP1900 Comfort

The TP1900 Comfort runs WinCC RT Advanced on an ARM-class processor with limited CPU budget for the rendering thread. Practical limits derived from Siemens application notes and field deployments:

• Maximum animated objects per screen: approximately 50 simultaneous Display/Appearance or Visibility animations without visible flicker at the default 500 ms acquisition cycle. The exact limit depends on the panel's other load (trend views, alarm logs, scripts).
• Layered rectangles (Solution C): keep each layer count below 6 per logical area; more than 6 stacked transparent objects can cause visible redraw artifacts during fast tag changes.
• Blinking property: do not stack more than 3 blinking rectangles on the same screen; the WinCC RT Advanced blink scheduler uses a single timer per panel and excessive subscribers can desynchronize.
• Acquisition cycle: 1 s is sufficient for human-operated status words. Dropping to 250 ms or lower offers no perceptible benefit and increases CPU load by 4×.

11. Migration Notes from V13 to V16 / V17 / V20

• The Bit selection for appearance option remains disabled by default in V14, V15, V15.1, V16, V17, and V20 to preserve the V13 behavior. Existing projects therefore keep the same gray-on-multi-bit behavior unless the option is deliberately enabled.
• WinCC RT Professional (introduced as a runtime option in V18 and continued in V19/V20) replaces the appearance-animation concept with Property animations driven by tag value ranges. See the official TIA Portal V20 help topic Dynamization with property animations (RT Professional) at docs.tia.siemens.cloud for the migration mapping.
• Layered visibility animations (Solution C) survive the migration untouched because they use only primitive screen objects and basic Visibility animations.
• Tag data types and acquisition cycles are preserved across project upgrades; verify that the PLC connection name has not changed if the project is re-tied to a different CPU.

12. Troubleshooting Matrix

13. Official Documentation References

• WinCC Advanced V13.0 SP1 — Configuring a new animation (Siemens support entry ID 109091876): documents the inspector-window workflow to attach an animation to a screen object.
• TIA Portal V20 — Dynamization with property animations (RT Professional): docs.tia.siemens.cloud — the equivalent mechanism when migrating to WinCC RT Professional.