Managing PROFIsafe Module Reintegration for ABB ACS880 Drives in PCS 7 F-Systems

In SIMATIC PCS 7 (V9.0 / V9.1) F-Systems paired with CPU 410-5H and ABB ACS880 drives via PROFINET with FSO safety modules, drive passivation following a power cut or communication glitch is cleared by applying a rising edge to the 'ACK_REI' (Reintegration Acknowledgment) input of the F-channel driver block or triggering the global acknowledgment block 'F_ACK_GL'. Unlike STEP 7 Distributed Safety which exposes an auto-generated F-I/O DB containing 'ACK_REI', PCS 7 F-Systems encapsulates fail-safe communication within F-channel drivers (such as F_CH_BI and F_CH_BO) and requires interconnecting an acknowledgment signal in the fail-safe CFC chart.

Executive Summary

In modern process automation, variable frequency drives (VFDs) frequently execute safety-instrumented functions—such as Safe Torque Off (STO), Safe Stop 1 (SS1), and Safely-Limited Speed (SLS)—over PROFIsafe industrial Ethernet. When integrating third-party drives such as the ABB ACS880 equipped with an FSO-12 or FSO-21 safety functions module into SIMATIC PCS 7 F-Systems, engineers often encounter an unexpected passivation lockout: after a power interruption or network blip on the drive, PROFIsafe communication halts and the drive calls for reintegration.

Engineers transitioning from STEP 7 Distributed Safety look for the familiar F-I/O instance data block where the ACK_REI tag is traditionally toggled. In SIMATIC PCS 7 F-Systems, however, fail-safe communication is managed strictly through CFC-based fail-safe channel driver blocks (F_CH_BI, F_CH_BO) and runtime group management. Because no standalone F-I/O DB is exposed in the block folder, the engineer cannot locate the reintegration variable, leaving the drive stuck in passivated fail-safe state (outputting substitute values 0). This guide explains how module passivation works in PCS 7 F-Systems and details the exact CFC interconnection required to enable safe operator reintegration.

Architecture and Fundamental Mechanics

The PROFIsafe communication and passivation architecture in PCS 7 F-Systems adheres to IEC 61508 / IEC 61511 functional safety standards:

PROFIsafe Telegram Lifecycle and Passivation:
- The ABB ACS880 FSO module exchanges cyclic safety telegrams (e.g., PROFIsafe Telegram 1) containing safety data, status bytes, and cyclic redundancy checks (CRC) with CPU 410-5H.
- If the drive suffers a power cut, cycle watchdog timeout, or CRC error, the safety runtime group passivates the module immediately, driving all fail-safe outputs to their defined safe state (0 or substitute values).
- When power and network communication recover, PROFIsafe transitions to 'reintegration request' status (QBAD = 1, REI_REQ = 1).
Distributed Safety vs PCS 7 F-Systems Architecture:
- In STEP 7 Distributed Safety, HW Config generates an independent DB for each F-I/O station (DB<F-I/O>), which contains variables PASS_ON, ACK_REI, and QBAD directly in user logic.
- In PCS 7 F-Systems, this functionality is abstracted into fail-safe channel driver blocks (F_CH_BI, F_CH_BO, F_CH_II) placed inside a dedicated F-Execution runtime group.
- Each F-channel driver contains an input pin ACK_REI (or coordinates with the F-System driver F_PS_BO).
Global and Operator Acknowledgment Mechanics:
- In accordance with safety guidelines, a faulted fail-safe device must never restart automatically without deliberate human intervention.
- PCS 7 F-Systems provides the F_ACK_GL (Global Acknowledgment) and F_ACK_OP blocks.
- Connecting a pulse from a WinCC operator pushbutton or an automation sequence to F_ACK_GL.ACK_GL broadcasts a synchronized acknowledgment pulse across all passivated F-channel drivers, clearing QBAD and restoring live process communication to the ABB ACS880.

Step-by-Step Implementation Procedure

Follow these steps to configure PROFIsafe reintegration for ABB ACS880 drives in PCS 7 F-Systems:

Configure ABB ACS880 FSO in HW Config:
- In SIMATIC Manager HW Config, install the official GSDML file for the ABB PROFINET adapter (FENA-21 or FPNO-21) with FSO-12/21.
- Insert the drive node onto the PROFINET IO system under CPU 410-5H.
- Add the appropriate PROFIsafe telegram module (e.g., 'PROFIsafe Telegram 1') and standard drive control telegram (e.g., Telegram 1 or Telegram 20).
- Assign a unique F-Destination Address (F_Dest_Add) and matching F-Source Address in the module properties.
- Save and compile HW Config.
Instantiate Fail-Safe Channel Driver Blocks in CFC:
- Open a fail-safe CFC chart (yellow chart header indicating F-Run group).
- From the PCS 7 F-Library, insert F_CH_BO for sending safety commands (e.g., STO/SS1 triggers) and F_CH_BI for reading safety status.
- Connect the block address inputs (VALUE) to the symbolic fail-safe I/O addresses defined in HW Config.
Configure Reintegration Acknowledgment (F_ACK_GL):
- In the fail-safe CFC chart, insert the block F_ACK_GL (FB390).
- Create an operator acknowledgment circuit: connect a standard boolean trigger from a WinCC pushbutton (via an F_QUBI or F_SWC_BO standard-to-failsafe conversion block) to F_ACK_GL.ACK_GL.
- (Alternatively): On each individual F_CH_BO block, connect the acknowledgment signal directly to the ACK_REI input pin.
Monitor Drive Reintegration Request:
- On the F_CH_BO block, observe output REI_REQ (Reintegration Request) and QBAD (Quality Bad).
- Route REI_REQ to the WinCC operator interface so operators receive an explicit visual prompt: 'Safety Drive Passivated - Press Acknowledge to Reintegrate'.
Compile Fail-Safe Program and Download:
- Select 'Chart > Compile > Charts as Program...'.
- Ensure the fail-safe compilation is successful and note the generated F-Signature.
- Download the safety program to the S7 controller with the Safety Password.
- Configure matching F-parameters on the ABB ACS880 drive using ABB Drive Composer Pro.

Verification

Verify normal operation: confirm that CPU 410-5H and the ABB ACS880 exchange safety data without alarms (QBAD = 0).
Simulate power loss: temporarily disconnect the 24 V DC auxiliary control power from the ABB ACS880 drive.
Observe CPU behavior: confirm that the F-channel driver asserts QBAD = 1 and REI_REQ = 1, and the drive faceplate displays 'Passivated'.
Restore power to the drive: confirm that PROFIsafe communication establishes, but the drive remains passivated until acknowledged.
Click the Reintegration Acknowledgment pushbutton on WinCC: verify that QBAD drops to 0, REI_REQ clears, and the drive returns to active operational state without requiring a hardware re-download.

Limitations and Operational Precautions

Automatic cyclic reintegration without operator acknowledgment violates functional safety standards (IEC 61508 / EN ISO 13849-1); ACK_REI must always require deliberate operator initiation. Ensure that the PROFIsafe watchdog timer (F_WD_Time) in HW Config accommodates worst-case network jitter without causing spurious trips. Safety hardware configurations, S7 F-Runtime licenses, and F-Systems software packages should be verified through an authorized Siemens distributor or the Siemens Industry Mall.

Engineer FAQ

Why is there no F-I/O DB in PCS 7 F-Systems?

PCS 7 F-Systems encapsulates fail-safe communication inside CFC F-channel driver blocks rather than generating standalone data blocks like STEP 7 Distributed Safety.

What block provides global reintegration in PCS 7 F-Systems?

The F_ACK_GL (FB390) block provides global reintegration acknowledgment across all fail-safe channels in the runtime group.

What output indicates that the ABB drive is ready for reintegration?

The REI_REQ (Reintegration Request) output on the F-channel driver block indicates that field communication is healthy and awaiting an acknowledgment pulse.