Mapping Operating Modes in CEMAT Drives vs Standard PCS 7 Library: The Functional Equivalent of QMAN_AUT

In SIMATIC PCS 7, the classic Standard Library motor block (FB66 MOTOR) uses output pin QMAN_AUT (1 = Automatic, 0 = Manual) to indicate the current operating mode. The CEMAT Minerals library drive block (C_DRV_1D) does not have a QMAN_AUT pin because CEMAT operates on a three-mode philosophy: Automatic, Manual, and Local. In C_DRV_1D, operating modes are reported via dedicated individual Boolean outputs: QAUT (Automatic Mode Active), QMAN (Manual Mode Active), and QLOC (Local Mode Active). To replicate QMAN_AUT behavior in downstream interlocking logic, connect the QAUT output directly or evaluate QAUT = 1.

Operating Mode Architectures: Standard Library FB66 vs CEMAT C_DRV_1D

In legacy SIMATIC PCS 7 systems (V5.x, V6.x, and V7.x), the classic Standard Library provided function block FB66 (MOTOR) for simple unidirectional drives. In FB66, operating modes were strictly binary: Automatic mode (logic from SFC or sequence logic) versus Manual mode (commands from the operator faceplate). The block provided a single output pin, QMAN_AUT, where 1 signified Automatic mode and 0 signified Manual mode.

When engineers migrate projects to the CEMAT Minerals & Mining Library or develop heavy material handling logic using C_DRV_1D, they frequently search for QMAN_AUT to feed downstream permissive logic and are surprised to find it absent. Understanding the design divergence between general chemical automation and cement plant automation clarifies this structure.

Why CEMAT Uses a Three-State Mode Philosophy (Automatic, Manual, Local)

Cement manufacturing facilities, quarries, and bulk conveyor terminals operate massive machinery spanning miles of terrain. Maintenance crews and field operators must frequently decouple equipment from central DCS control for maintenance, cleaning, or physical tracking alignment. Consequently, CEMAT mandates three distinct operating modes:

Automatic Mode (QAUT): The drive is controlled entirely by upstream group start sequences (C_GROUP), route selection logic (C_ROUTE), and interlocking conditions.
Manual Mode (QMAN): The central control room operator commands the drive individually from the WinCC faceplate. Group start commands are ignored, but essential safety interlocks remain strictly active.
Local Mode (QLOC): The drive is operated directly from physical pushbuttons mounted on the field local control station (LCS) near the motor. Central start commands are locked out, and operational interlocks may be bypassed according to plant rules.

CEMAT Mode Output Signals: QAUT, QMAN, and QLOC Mechanics

Because an equipment drive can exist in any of three mutually exclusive states, a single binary output pin like QMAN_AUT is mathematically insufficient. If a drive is in Local mode, asserting 0 would falsely imply it is in Manual mode.

In C_DRV_1D and C_DRV_2D, the operating states are exposed via discrete outputs:

QAUT = 1: Drive is in Automatic Mode.
QMAN = 1: Drive is in Manual Mode.
QLOC = 1: Drive is in Local Mode.

Additionally, the block provides the QSTART output (drive running signal) and mode feedback status words for WinCC.

Logic Migration and Adaptation Workflow

To adapt existing logic that previously relied on FB66's QMAN_AUT:

If Downstream Logic Requires 'Is in Automatic': Interconnect C_DRV_1D.QAUT directly to the downstream permissive input pin. When the drive is in Automatic, QAUT provides logic 1.
If Downstream Logic Requires 'Is in Manual': Interconnect C_DRV_1D.QMAN to the destination logic pin.
If Downstream Logic Evaluates Non-Automatic (Manual OR Local): Use an OR logic block in CFC combining QMAN and QLOC, or invert QAUT using an inversion flag (NOT QAUT).

Drive Block Operating Mode Signal Comparison

The following table compares mode handling across major Siemens drive libraries:

Library / BlockAutomatic Mode PinManual Mode PinLocal Mode PinBinary Combined PinStandard Library FB66 (MOTOR)Inferred (QMAN_AUT = 1)Inferred (QMAN_AUT = 0)Not Supported nativelyQMAN_AUT (1=Auto, 0=Man)APL FB1823 (MotL)AutAct (1=Auto)ManAct (1=Man)LocalAct (1=Local)None (Individual pins)CEMAT FB1001 (C_DRV_1D)QAUT (1=Auto)QMAN (1=Man)QLOC (1=Local)None (Use QAUT or QMAN)CEMAT FB1002 (C_DRV_2D)QAUT (1=Auto)QMAN (1=Man)QLOC (1=Local)None (Separate Direction Pins)

Verification

Verify mode output transitions through the following steps:

Open the CFC chart containing C_DRV_1D online in Test Mode.
In WinCC Runtime, open the motor faceplate and switch the drive to Automatic. Confirm in CFC that QAUT = 1, QMAN = 0, and QLOC = 0.
Switch the drive to Manual from the faceplate. Confirm that QAUT = 0, QMAN = 1, and QLOC = 0.
Engage the physical local key switch on the field panel (or simulate input ESPO). Confirm that QAUT = 0, QMAN = 0, and QLOC = 1.
Verify that downstream route or interlocking blocks respond correctly to the state transitions.

Limitations and Operational Precautions

Consider these operational rules when adapting CEMAT drive modes:

Never Assume NOT QMAN Means Automatic: On C_DRV_1D, if a motor is switched to Local mode, QMAN is 0, but the motor is NOT in Automatic; always check QAUT explicitly.
Group Mode Hierarchy: In CEMAT, switching a parent group block (C_GROUP) to Automatic or Manual commands all member drives simultaneously unless an individual drive is locked out in Local mode.
Local Mode Safety Interlocks: Ensure that essential safety interlocks (EEVG) remain active even in Local mode to prevent personnel injury or conveyor structural damage.

Engineer FAQ

How do operators switch between Automatic and Manual in CEMAT?

Operators click the operating mode buttons in the standard CEMAT faceplate (@PG_C_DRV_1D_STANDARD.PDL) or the plant central control room commands whole groups via C_GROUP.