Resolving Unresolved Process Tags in SIMATIC BATCH Recipe Transitions with TAG_COLL

In SIMATIC PCS 7 with SIMATIC BATCH, an issue where recipe transitions using the TAG_COLL block display a question mark with a red strikethrough occurs because the process variable reference has not been propagated from the automation station into the SIMATIC BATCH engineering database. Resolving this transition failure requires verifying TAG_COLL plant hierarchy placement, executing an AS chart compilation and OS compile, transferring messages to BATCH, and generating updated BATCH Types in BatchCC.

Architecture of Recipe Transitions and TAG_COLL in SIMATIC BATCH

In automated batch manufacturing conforming to ISA-88, recipe steps transition based on process condition evaluations (such as vessel temperature reaching 85 °C, tank level dropping below 10%, or agitator speed stabilizing).

In SIMATIC BATCH:
* Transition Logic Evaluation: Transitions in master and control recipes can evaluate both phase completion statuses and continuous plant process variables.
* The TAG_COLL Block: To route continuous analog or digital measurements from CFC charts into SIMATIC BATCH recipes, Siemens provides the TAG_COLL (FB 264 / FB 664) function block.
* Multiplexed Tag Collection: TAG_COLL collects up to 16 process values (PV_In1 to PV_In16) and registers them as technological process variables accessible to the BATCH recipe compiler.

The Failure Mechanism: Why Transitions Display Question Marks with Red Lines

When a recipe author inserts a transition condition in BatchCC and browses for a process variable, the editor may display ? overlaid with a red diagonal strikethrough:
1. Unsynchronized Type Generation: Even if TAG_COLL is correctly interconnected in CFC, SIMATIC BATCH cannot resolve the tag pointer until the block attributes are compiled and imported into the BATCH Types database.
2. Plant Hierarchy Misalignment: If TAG_COLL resides in a plant hierarchy folder not marked with the BATCH unit or equipment module attribute, the BATCH compiler ignores the block during type generation.
3. Missing OS Message Transfer: BATCH relies on the WinCC OS database to establish communication tag channels; omitting OS compilation prevents BATCH from binding runtime tag handles.

Step-by-Step Procedure: Synchronizing TAG_COLL with SIMATIC BATCH

Verify Plant Hierarchy Placement:
* In SIMATIC Manager, ensure the CFC chart containing TAG_COLL is located within a plant hierarchy folder designated as a BATCH Unit or Neutral Folder with BATCH relevance.
Interconnect Process Values:
* Open the CFC chart. Connect continuous process signals (e.g., MonAnL.PV_Out or raw analog inputs) to TAG_COLL.PV_In1 through PV_In16.
* Configure descriptive parameter identifiers on PV_InX pins.
Compile Charts and OS:
* Execute Chart -> Compile -> Entire Program.
* Execute Compile OS to update the WinCC tag database.
Generate BATCH Types in SIMATIC Manager:
* In the Multiproject tree, select the BATCH application folder.
* Right-click and choose SIMATIC BATCH -> Open.
* Run Options -> Transfer Messages....
* Run Options -> Generate BATCH Types. Verify that the log reports zero errors and lists TAG_COLL process tags.
Compile and Download BATCH Data:
* Select Compile BATCH and Download BATCH.
Update Recipe in BatchCC:
* Open BatchCC. Open the master recipe and open the transition properties.
* Re-select the process variable from the updated tag browser. The red strikethrough disappears, replaced by the resolved variable name and comparison operator.

Configuring Transition Logic in the BatchCC Recipe Editor

In the transition condition builder, define relational operators: PV >= Setpoint or PV <= Limit.
Combine multiple conditions using boolean AND / OR logic gates within the transition expression.
Configure timeout safety monitoring to trigger a batch hold if process transitions fail to satisfy within expected recipe time windows.

Verification

In BatchCC, validate the master recipe: confirm that the recipe validation engine reports No errors found.
Release the recipe for production and create a test control recipe.
Start batch execution: verify that when the physical sensor reaches the setpoint condition, the transition changes state to TRUE and execution progresses smoothly to the next recipe phase.

Limitations and Operational Precautions

Avoid High-Frequency Polling: TAG_COLL is designed for recipe transition checkpoints, not continuous high-frequency closed-loop regulation.
Data Type Matching: Ensure that analog process values connected to PV_InX match the floating-point REAL format expected by BATCH transition comparators.
Synchronized Redundant Servers: If using redundant BATCH servers, ensure BATCH compilation is downloaded to both servers before starting production.

Engineer FAQ

What does a question mark with a red line mean in a BATCH transition?
It indicates that the assigned process variable reference is unresolved or missing in the BATCH database.
Which block connects CFC process variables to SIMATIC BATCH?
The TAG_COLL (FB 264 / FB 664) function block collects process variables for BATCH recipes.
How many process values can a single TAG_COLL block collect?
A single TAG_COLL block multiplexes up to 16 process values (PV_In1 to PV_In16).
Why did TAG_COLL not appear in the BatchCC tag browser?
Because BATCH Types were not regenerated after compiling the CFC chart and OS.
Is an OS compilation required before BATCH type generation?
Yes, OS compilation is mandatory to update WinCC tag records queried by SIMATIC BATCH.
Can digital signals be evaluated in BATCH transitions?
Yes, binary signals connected to TAG_COLL can be evaluated for TRUE/FALSE transition states.
Does updating BATCH Types abort running batches?
No, updating types does not abort running batches, but newly added tags apply only to newly created recipes.
Can BATCH transitions evaluate mathematical expressions?
Yes, transitions support relational comparisons, arithmetic offsets, and boolean logic.
Where are BATCH recipe definitions stored?
Recipes are stored in the SIMATIC BATCH database on the central BATCH server.
Where should SIMATIC BATCH license requirements be validated?
BATCH server, client, and recipe licenses must be verified in the Siemens Industry Mall.

Technical References

Siemens Manual: SIMATIC Process Control System PCS 7 SIMATIC BATCH (A5E39265215-AA).
Siemens Industry Online Support Entry ID 109801081: Configuring Process Variables in SIMATIC BATCH Transitions.
ANSI/ISA-88.01: Batch Control Models and Terminology.