Detecting Automatic Mode in CEMAT Drive Blocks (C_DRV_1D): Status Word Decoding and Equivalent of QMAN_AUT

In SIMATIC PCS 7 CEMAT drive blocks (C_DRV_1D and C_DRV_2D), there is no dedicated binary output named QMAN_AUT as found in standard APL blocks (MotL). To detect in CFC when a CEMAT motor is in Automatic mode, evaluate the drive's internal status structure. In modern CEMAT versions, read output AUT_ON or decode bit 1 of the status word STATUS32_1 (STA_AUT). Alternatively, in legacy CEMAT, evaluate the operating mode inversions: when both Manual mode (MAN_ON == 0) and Local mode (LOC_ON == 0) are inactive and the drive is not Out of Service (OOS == 0), the drive is confirmed to be in Automatic position.

APL vs CEMAT Operating Mode Architecture: The Missing QMAN_AUT

Engineers transitioning from standard SIMATIC PCS 7 Advanced Process Library (APL) to the CEMAT Minerals & Mining library frequently search for the ubiquitous output parameter QMAN_AUT (or AutAct / ManualAct). In APL, QMAN_AUT delivers a clear binary indicator (1 = Auto, 0 = Manual) that is easily wired into interlocks, sequencing SFCs, or external SCADA telemetry.

In CEMAT, drive blocks (C_DRV_1D for unidirectional drives and C_DRV_2D for bidirectional drives) were engineered around highly condensed technological data structures optimized for mineral processing group sequencing (C_GROUP). Rather than exposing dozens of discrete binary mode outputs that clutter CFC margins, CEMAT packs operational states into structured 32-bit DWORD status words, requiring specific decoding techniques.

CEMAT Operating Modes: Automatic, Manual, Local, and Out of Service

A CEMAT drive operates in one of four mutually exclusive operating modes:

Automatic Mode: The drive is controlled automatically by group start/stop sequences (C_GROUP) and route control logic.
Manual Mode: The drive is operated individually by control room operators from the WinCC faceplate (C_DRV_1D standard view).
Local Mode: The drive is controlled by field personnel via physical start/stop pushbuttons positioned adjacent to the physical motor.
Out of Service (OOS): The drive is isolated for mechanical or electrical maintenance, suppressing alarms and interlocking.

Because a drive cannot be in Auto and Manual simultaneously, detecting Automatic mode requires reading the positive auto flag or evaluating the absence of all non-automatic modes.

Decoding the CEMAT 32-Bit Status Words (STATUS32_1 / STATUS32_2)

In CEMAT V7.x, V8.x, and V9.x, the block outputs STATUS32_1 and STATUS32_2 contain the full operational state of the machine. To extract individual status flags in Continuous Function Charts:

In STATUS32_1, bit positions correlate directly to operating modes:
Bit 1 (STA_AUT): Drive is in Automatic Mode (1 = Active).
Bit 2 (STA_MAN): Drive is in Manual Mode (1 = Active).
Bit 3 (STA_LOC): Drive is in Local Mode (1 = Active).
Bit 4 (STA_OOS): Drive is Out of Service.
Engineers can connect C_DRV_1D.STATUS32_1 to a bit-demultiplexer block (such as standard STEP 7 BITS_32 or CEMAT status extractor C_STATUS) to unpack Bit 1 into a clean boolean signal.

Evaluating Mode Flags: AUT_ON, MAN_ON, and LOC_ON Logic

In modern releases of CEMAT, individual boolean interface signals are exposed on the block interface for technological convenience:

Parameter AUT_ON: In CEMAT V8.1 and later, parameter AUT_ON is exposed on C_DRV_1D and asserts 1 whenever the drive is in Automatic mode. If AUT_ON is hidden in CFC, unhide it via Object Properties -> Parameters -> Visible.
Boolean Complement Logic (Legacy CEMAT V6 / V7): If working on legacy versions where AUT_ON is not exposed, Automatic mode can be derived with absolute mathematical certainty using standard logic gates:
Is_Auto = (NOT MAN_ON) AND (NOT LOC_ON) AND (NOT OOS)
Connecting MAN_ON, LOC_ON, and OOS into a NOR gate generates the exact functional equivalent of QMAN_AUT.

Comparative Signal Matrix: APL MotL vs CEMAT C_DRV_1D Mode Outputs

The following table compares mode detection parameters between standard APL and CEMAT libraries:

| Operational Dimension | Standard PCS 7 APL (MotL) | CEMAT Unidirectional Drive (C_DRV_1D) |
|---|---|---|---|
| Direct Auto Output | QMAN_AUT (or AutAct) | AUT_ON (Visible in modern CEMAT) |
| Status Word Bit | Status1.Bit0 | STATUS32_1.Bit1 (STA_AUT) |
| Manual Mode Output | ManualAct | MAN_ON / STATUS32_1.Bit2 |
| Local Mode Output | LocalAct | LOC_ON / STATUS32_1.Bit3 |
| Out of Service Output| OosAct | OOS / STATUS32_1.Bit4 |
| Group Linkage | External interlock wiring | Native group pointer C_GROUP (LNK_GRP) |

Step-by-Step CFC Interconnection and Extraction Workflow

Follow this procedure to extract the Automatic mode signal in CFC:

Open the CFC chart containing the C_DRV_1D instance.
Double-click the block or right-click and select Object Properties.
In the I/Os tab, search for parameter AUT_ON.
If present and hidden, check the box in the Visible column. Click OK.
If AUT_ON is absent in your library version, insert a standard boolean NOT/AND gate or CEMAT C_STATUS bit unpacker.
Connect C_DRV_1D.MAN_ON and C_DRV_1D.LOC_ON to the inputs of a 2-input NOR gate (NOR block from PCS 7 Basis Library).
The output of the NOR gate provides the exact QMAN_AUT equivalent signal, ready for wiring to downstream sequences or telemetry.

Verification

Verify mode detection in CFC and WinCC Runtime:

Open the motor faceplate in WinCC Runtime and click Auto. Confirm that the drive switches to Automatic mode.
In CFC test mode, confirm that AUT_ON (or your NOR gate output) transitions to 1 (True).
In WinCC Runtime, click Manual and verify that AUT_ON immediately drops to 0 (False).
Switch to Local mode via field simulation; confirm that the signal remains 0.
Verify that downstream interlocking correctly recognizes the Auto signal without chattering.

Limitations and Operational Precautions

Adhere to the following operational precautions:

Never Force Operating Modes in Logic: Do not attempt to force a drive into Auto mode by writing directly to AUT_ON; mode switching in CEMAT must be executed via command inputs (AUTO_ON, MANU_ON) or group commands.
Group Sequence Priority: Remember that in CEMAT, placing a motor in Auto does not automatically start the motor; the motor starts only when the parent group (C_GROUP) executes its automated start sequence.
Hidden Pin Persistence: Parameters made visible in CFC remain visible across delta compilations, but updating block types from Master Data Library may reset visibility attributes if not configured in the template.

Engineer FAQ

Can I make the AUT_ON pin visible on existing CFC charts?

Yes. In CFC, open the block's Object Properties, find AUT_ON in the I/Os tab, check the Visible column, and click OK.

How do I extract individual bits from the STATUS32_1 status word?

Interconnect STATUS32_1 to the input of a BITS_32 demultiplexer block from the standard S7 library or use the CEMAT C_STATUS block.

Does switching a CEMAT drive to Automatic mode cause it to run immediately?

No. In CEMAT, Automatic mode simply authorizes the drive to be started by its parent group sequence (C_GROUP). The motor starts only when group start conditions are met.