Selecting Recipes in WinCC Professional via PLC Control Tags

Overview

WinCC Professional (TIA Portal, RT Professional runtime) does not expose the SetDataRecordPLC function that exists in WinCC Comfort/Advanced. Engineers migrating a Comfort Panel HMI application to a PC-based WinCC Professional runtime, or those consolidating multiple Advanced panels onto a single SCADA station, must re-implement the "load a specific data record into the connected PLC tags" action using either the Recipe Control Tags (ID + Job) or the C-script User Archive (UA) standard functions.

This reference shows how to drive the recipe system from a custom selection interface using two integer PLC tags (RecipeNumber and DataRecordNumber) and the WinCC Professional recipe control tag mechanism, including commissioning checks and a fault matrix.

Prerequisites

• TIA Portal V16 or later with WinCC Professional installed.
• Configured HMI device of type "WinCC Professional" (PC-based or RT Professional).
• Configured Recipes in the project tree (project HMI device → "Recipes").
• Connection to the PLC with at least two writable integer tags exposed to the HMI (e.g., RecipeNumber Int and DataRecordNumber Int).
• For the C-script path: a C script editor window in a screen or a global script. (C scripting is supported in WinCC Professional; VBScript is supported but does not expose the ua* functions the same way.)

Recipe System Differences: Advanced vs Professional

WinCC Comfort/Advanced stores recipes in a flat, panel-local data structure and exposes them through area pointers (RecipeNumber, DataRecord, DataRecordName, UserData) plus the high-level function SetDataRecordPLC. WinCC Professional uses a fundamentally different model:

Because the area pointer "job" concept is gone, the equivalent of an Advanced button calling SetDataRecordPLC becomes a two-step in WinCC Professional: (1) write the desired recipe number into the recipe's control tag for "ID", then (2) pulse a job code into the recipe's "Job" control tag to trigger the transfer.

Method 1 — Recipe Control Tags (Recommended)

Every recipe in a WinCC Professional HMI device has four automatically-created control tags that you can read and write from the PLC or from scripts. These are configured in the recipe's properties, not in the PLC.

Step 1 — Inspect the auto-generated control tags

1. Open the project tree, expand your HMI device, then Recipes.
2. Select a recipe (e.g., Recipe_1).
3. In the Inspector window choose Properties → Control tags.
4. Note the four tag names. By default they are:
   • <RecipeName>_ID — DWORD, recipe number
   • <RecipeName>_Job — DWORD, command code
   • <RecipeName>_Status — DWORD, runtime state
   • <RecipeName>_Error — DWORD, error code

Step 2 — Configure recipe elements and their process tags

1. Select the Recipe elements tab in the lower area of the Recipes editor.
2. For each element, set Name, Data type, and most importantly the Tag column — the HMI or PLC tag whose value is read/written when the record is loaded or saved. This corresponds to the Process tag in Advanced.
3. Add one element row per value that must transfer to the PLC.

Reference: Creating Recipe Elements and Data Records (RT Professional).

Step 3 — Create the runtime data records

1. Switch to the Data records tab of the recipe.
2. Click Add to create a new data record row. Enter the Display name (operator-visible) and the internal record number.
3. Populate the cells of the data record with the values that should be written to the process tags when the record is loaded.

Step 4 — Build the custom selection UI

On the screen where the operator selects a recipe/data record:

1. Add two I/O fields bound to your two PLC tags (RecipeNumber and DataRecordNumber) — these are the tags already present in your PLC logic.
2. Add a Button labelled "Load". Configure a Click event using the Set tag function or a small C/VBS script that performs the three writes below.

Step 5 — Drive the recipe with control tags

The sequence executed when the operator clicks "Load" is:

1. Write the desired recipe number into <RecipeName>_ID.
2. Write the desired data record number into <RecipeName>_ID (recipe number is the high word in some firmware; in current versions a single DWORD carries the record number — see job table below).
3. Write a job code (e.g., 6 = "Load data record to PLC") into <RecipeName>_Job.
4. Poll <RecipeName>_Status; the runtime clears the job bit when complete.
5. Evaluate <RecipeName>_Error for fault codes.

Control tag job codes (RT Professional)

Step 6 — C-script example (button click)

// Trigger "Load data record to PLC" via the control tag job interface
// Recipe: "Recipe_1"
// Control tags: "Recipe_1_ID", "Recipe_1_Job"

DWORD dwRecipe   = GetTagWord("HMI_RecipeNumber");   // from PLC selection
DWORD dwRecord   = GetTagWord("HMI_DataRecordNumber");

// Some firmware versions pack record number in the high word of _ID.
// If your project uses the high-word convention:
//   DWORD dwID = (dwRecipe << 16) | (dwRecord & 0xFFFF);
// Otherwise _ID holds only the recipe number:
DWORD dwID = dwRecord;

SetTagDWORD("Recipe_1_ID",  dwID);
SetTagDWORD("Recipe_1_Job", 6);   // 6 = "Load data record to PLC"

For a PLC-driven solution, write the same two HMI control tags from a job bit in the PLC: set Recipe_1_ID first, then raise a pulse that writes 6 to Recipe_1_Job for one cycle, then clear it.

Method 2 — C-Script User Archive (UA) Functions

When a single selection interface must drive multiple recipes, or when the recipe name must be passed dynamically (e.g., selected from a string tag), the cleaner path is the C-script User Archive API. These are the same functions used in legacy WinCC Classic against the "User Archive".

UA function reference (RT Professional)

Step-by-step UA path

1. Open the screen that contains the selection UI.
2. Open the C editor for the "Load" button Click event.
3. Insert the script shown below.
4. Compile the script (the editor reports syntax errors inline).

C-script example — load a record to PLC tags

// Load a recipe's data record into process tags using the UA API
// Recipe: "Recipe_1"; record number comes from PLC tag HMI_DataRecordNumber

#include "apdefap.h"

void OnClickLoad(char* lpszPictureName, char* lpszObjectName)
{
    long  lRecord   = GetTagWord("HMI_DataRecordNumber");   // 1-based
    long  lJob      = 6;                                     // not used by UA path, but kept for parity
    BOOL  bOK       = FALSE;

    // 1. Connect to the archive backing "Recipe_1"
    long lArchID = uaConnect("Recipe_1");
    if (lArchID == 0) {
        SetTagWord("HMI_LoadError", 1001);  // connection failed
        return;
    }

    // 2. Read the requested record into the runtime cache
    if (uaGetRecord(lArchID, lRecord) == TRUE) {
        // 3. Push each archive field into the matching process tag
        //    Field order in uaGetFieldValue is 1-based and matches the
        //    recipe element order configured in the editor.
        SetTagFloat("PLC_Tag_Setpoint",  uaGetFieldValueFloat(lArchID, 1));
        SetTagWord ("PLC_Tag_Mode",      uaGetFieldValueLong (lArchID, 2));
        SetTagFloat("PLC_Tag_Tolerance", uaGetFieldValueFloat(lArchID, 3));
        bOK = TRUE;
    }

    // 4. Disconnect
    uaDisconnect(lArchID);

    // 5. Report
    SetTagWord("HMI_LoadError", bOK ? 0 : 1002);  // 1002 = record not found
    SetTagBit ("HMI_LoadDone",  bOK);
}

PLC-Side Coordination

For either method, the PLC must hand-shake cleanly with the HMI to avoid double triggers and to surface errors to the operator. A standard pattern is:

Use the PLC LoadActive signal as an interlock: the operator selection should be disabled while a load is in progress. This prevents the operator from changing RecipeNumber between the ID and Job writes.

Verification and Commissioning

1. Tag visibility test. In RT Professional runtime, open the Tag simulator or use a temporary I/O field to confirm the four recipe control tags (_ID, _Job, _Status, _Error) are online and writable.
2. Single-record load test. Manually write recipe number = 1, record number = 1, then write job = 6. Verify in the PLC that each mapped process tag updates to the configured data record value within one scan cycle of LoadDone.
3. Error path test. Set record number to a value beyond the configured records and trigger job = 6. Confirm LoadError returns a non-zero code (typically 0x8004xxxx-range codes for record-not-found, or a documented numeric code per your Information System).
4. UI lock test. With LoadActive TRUE, attempt to change RecipeNumber from the operator screen. The selection should be rejected or visually disabled.
5. Restart persistence. Restart the RT Professional runtime. Recipe data records must reload from the configured database. Method 1 automatically re-reads; Method 2 (ua*) requires the script to uaConnect on each invocation, which is the safe default.

Troubleshooting Matrix

Comparison of the Two Methods

References Inside the Documentation Set

Open the TIA Portal Information System and navigate:

• Visualize Processes → Working with recipes → RT Professional — for editor and control tag specifics.
• Visualize Processes → Working with recipes → RT Professional → Data transfer to PLC → Control tags — the definitive source for the job code table above.
• Visualize Processes → Working with recipes → RT Professional → User Archive functions — full ua* function reference.

For recipes on Comfort/Advanced panels (used here only for comparison), see Using the advanced recipe view (Basic Panels, Panels, Comfort Panels, RT Advanced).