Integrating Danfoss VLT FC 300 and FC 302 Inverters into SIMATIC PCS 7

Integrating Danfoss VLT AutomationDrive FC 300 and FC 302 variable frequency drives into SIMATIC PCS 7 can be accomplished either via generic PROFIBUS-DP / PROFINET GSD/GSDML files using standard PPO telegrams with the APL 'MotSpdCL' block, or by deploying the official Siemens 'Danfoss VLT APL Function Block Library'. The dedicated Siemens library provides pre-engineered driver blocks, Maintenance Station asset diagnostics, and native WinCC APL faceplates for seamless operating mode and parameter control.

Executive Summary

In industrial processing plants, variable frequency drives (VFD) from third-party manufacturers—most notably Danfoss VLT AutomationDrive FC 300, FC 301, and FC 302—are widely installed for pump, fan, and conveyor speed control. When modernizing or expanding facilities controlled by SIMATIC PCS 7 (V8.0 through V9.1), automation engineers must integrate these drives into the DCS architecture over PROFIBUS-DP or PROFINET.

Engineers frequently search the standard PCS 7 libraries for native Danfoss faceplates, only to discover that the factory Advanced Process Library (APL) includes blocks exclusively for Siemens drives (such as SINAMICS and MICROMASTER). To integrate Danfoss drives, engineers have two primary pathways: engineering a custom adapter using standard APL MotSpdCL and PROFIBUS PPO profiles, or procuring the certified Siemens Danfoss VLT Function Block Library. This article compares both engineering methodologies, detailing telegram configurations, driver generation, and faceplate integration.

Architecture and Fundamental Mechanics

The communication architecture between Danfoss FC 300/302 drives and SIMATIC S7-400 / CPU 410 controllers operates over standardized fieldbus communication profiles:

Fieldbus Telegram Standards (PROFIdrive and PPO Types):
- Danfoss VLT FC series drives support the PROFIdrive standard and Parameter-Process Data Object (PPO) telegram formats:
- PPO Type 3: 2 words PZD (Process Data only: Control Word CTW, Speed Reference MRV / Status Word STW, Actual Speed MAV). Ideal for basic speed control.
- PPO Type 4: 6 words PZD (Process Data with auxiliary status: Motor Current, Torque, Frequency, Fault Codes).
- PPO Type 1 / 2: Combines PZD with PKW (Parameter Identification Value) words for reading and writing drive internal parameters online.
Pathway A: Custom Integration Using Standard APL MotSpdCL:
- The drive is inserted into HW Config using the vendor GSD/GSDML file (Danfoss FC 300).
- In CFC, the engineer deploys the standard APL drive block MotSpdCL (Motor with Speed Control).
- Because MotSpdCL expects standard Siemens PROFIdrive bit layouts, the engineer must build a small bit-mapping adapter in CFC (or SCL) to translate Danfoss Control Word bits (e.g., bit 0 coasting stop, bit 1 quick stop, bit 2 DC brake) to the inputs of MotSpdCL and scale the 0-16384 (16#4000 = 100%) speed reference.
- Disadvantage: Standard PCS 7 Driver Generator cannot generate automatic maintenance diagnostics for third-party GSD devices.
Pathway B: Official Siemens Danfoss APL Library:
- Siemens Industry Services provides an engineered solution: the SIMATIC PCS 7 Function Block Library for Danfoss VLT (contact: [email protected]).
- Features: Includes dedicated AS function blocks (e.g., DRV_DANF), full PCS 7 Driver Generator integration (@CFC diagnostic driver synthesis), asset management integration with PCS 7 Maintenance Station, and complete WinCC APL-compliant faceplates displaying actual current, speed, frequency, thermal load, and specific Danfoss fault codes.
- Commercial Structure: Licensed per plant, typically bundled with a 5-year maintenance and update service contract.

Step-by-Step Implementation Procedure

Follow these steps to integrate Danfoss FC 300 / FC 302 drives into SIMATIC PCS 7:

Method A: Custom Integration with Standard APL MotSpdCL
1. Install Danfoss GSD/GSDML in HW Config:
- Download the official GSD file (PROFIBUS: DANF0407.GSD or PROFINET: GSDML-V2.3-Danfoss-FC-*.xml) from Danfoss.
- In HW Config, select 'Options > Install GSD Files...'.
- Locate the drive in the catalog: PROFIBUS-DP > Additional Field Devices > Drives > Danfoss > FC 300.
- Insert the drive onto the fieldbus line, assign an address, and configure the module configuration: select PPO Type 3 (or PPO Type 4).

Map Process Image Addresses in HW Config:
- Note the assigned I/O addresses: Input words (e.g., IW 512 Status Word, IW 514 Actual Speed) and Output words (e.g., QW 512 Control Word, QW 514 Speed Setpoint).
- Save and compile HW Config.
Implement Logic in CFC with MotSpdCL:
- In CFC, place MotSpdCL from the PCS 7 APL.
- Place channel driver blocks Pcs7DiIn / Pcs7DiOu or an SCL bit-adapter block.
- Connect MotSpdCL.Fwd and Rev to construct the Danfoss Control Word (CTW):
- Bit 3: Coasting stop inverse (must be set to 1 for operation).
- Bit 4: Quick stop inverse (must be set to 1 for operation).
- Bit 6: Enable ramp.
- Bit 10: Data valid.
- Connect MotSpdCL.SP_Out to QW 514 (scale 0-100% to 0 - 16384).
- Read Status Word (IW 512): map Bit 3 (Trip/Fault) to MotSpdCL.Trip, and IW 514 to MotSpdCL.Rbk.

Method B: Deploying the Siemens Danfoss VLT APL Library
1. Procure and Install the Library:
- Procure the library package and license from Siemens ([email protected]).
- Run the library setup installer on the Engineering Station and OS Servers.

Configure Drive with Library Blocks:
- In HW Config, select the specific Danfoss library catalog profile.
- In CFC, drag the library drive block (DRV_DANF) into the chart.
- Connect the I/O start address to the block's LADDR input parameter.
- Compile charts with 'Generate module drivers' enabled. The PCS 7 Driver Generator automatically generates the diagnostic communication channels.
Compile and Deploy OS Faceplates:
- Execute an AS-OS compile.
- Open WinCC Explorer: the Danfoss block icons (@DRV_DANF) and APL faceplates are automatically instantiated in the graphics hierarchy.
- Download project to OS Servers and AS controllers.

Verification

In HW Config online view, confirm the Danfoss FC 300/302 slave station reports green healthy communication without bus faults.
On the physical Danfoss drive display (LCP), verify that the control word indicates 'Remote / Bus Control'.
In WinCC OS Runtime, open the drive faceplate: switch to 'Manual' mode, enter a setpoint of 50%, and click 'Start'.
Confirm that the drive ramps up smoothly to 25 Hz (50% speed) and that actual feedback speed matches the setpoint.
Trigger a test drive warning or fault: verify that the APL faceplate alarms and reports the exact trip condition in the WinCC Alarm Logging list.

Limitations and Operational Precautions

Custom GSD integration requires careful testing of drive stop modes; Danfoss drives require specific bits (such as Coasting Inverse Bit 3) held high, otherwise the drive will coast to stop and refuse to run. Custom GSD integrations do not provide automatic Maintenance Station asset diagnostics. All third-party hardware integration libraries, service contracts, and software licenses must be validated with an authorized Siemens distributor or the Siemens Industry Mall.

Engineer FAQ

Does the standard PCS 7 APL include native Danfoss faceplates?

No. The standard APL includes faceplates for Siemens drives (SINAMICS, MICROMASTER). Danfoss drives require custom mapping to MotSpdCL or purchasing the official Siemens Danfoss VLT APL Library.

Where can I purchase the official Siemens Danfoss VLT Library?

The library is available through Siemens Industry Services and can be requested via email at [email protected] or through an authorized Siemens sales representative.

What PPO telegram type is most commonly used for basic speed control?

PPO Type 3 (consisting of 2 words in and 2 words out: Control/Status Word and Speed Setpoint/Actual) is standard for simple speed-regulated applications.

Why does my Danfoss drive show 'Auto Remote' but refuse to start from MotSpdCL?

Danfoss Control Words require Bit 3 (Coasting Stop Inverse) and Bit 4 (Quick Stop Inverse) to be held at logic 1. If either bit is 0, the drive locks in a coasted state.