Suppressing SINAMICS G150 F01910 Fault on PROFIBUS PLC Power-Off

The SINAMICS G150 drive family is widely deployed for variable-speed control of medium-voltage and large low-voltage induction motors. When integrated with a SIMATIC S7 PLC over PROFIBUS DP, the drive expects continuous process data exchange. If the PLC is de-energized while the drive remains online, the fieldbus telegram stream is interrupted and the drive raises fault F01910 (fieldbus setpoint timeout), forcing the drive into a fault-off state. This article documents four field-proven methods to manage F01910 cleanly when the controller is cycled, including parameter-level suppression, automatic Command Data Set (CDS) switching, DP-slave deactivation from the PLC, and a hard-wired LOCAL/REMOTE topology.

1. System Context and Affected Components

The failure scenario assumes the following minimum configuration:

• Drive: SINAMICS G150 (Control Unit CU320-2 DP), firmware V4.5 or higher. The methods described also apply to SINAMICS S120, G120, and G130 with CU320-2 DP, as the parameter set is largely shared.
• Fieldbus: PROFIBUS DP, drive on a DP-Slave slot with standard telegram type (commonly PZD 2/2 or PZD 4/4).
• Controller: SIMATIC S7-1200 (FW V3.0, configured in TIA Portal V12) or SIMATIC S7-300/400 with SIMATIC Manager. The S7-1200 supports the D_ACT_DP instruction as of FW V3.0, but the call signature differs from SFC12 in classic Step 7.
• I/O extension: TM31 Terminal Module (8 DI, 4 DO, 2 AI, 2 AO, 1 relay, 1 KTY/PTC input), which provides the hard-wired LOCAL fallback path.
• Command Data Sets: Two CDS configured so the drive can hold one setpoint source for PLC control and one for terminal control.

2. Understanding Fault F01910

F01910 is raised by the PROFIBUS / PROFINET board firmware when no valid setpoint telegram is received within the configured telegram failure time. The relevant parameters are:

When the PLC is powered off, the PROFIBUS line transitions to its idle state (no token, no telegrams), the CU320-2 DP detects the gap, r2043.0 transitions to 1, and the drive raises F01910. The default response is OFF1, which ramps the drive down according to p1121. This is correct safety behaviour but is undesirable when the PLC is being intentionally de-energized for service and the drive is intended to remain controlled from the TM31 in LOCAL mode.

3. Root Cause Analysis: Why F01910 Appears on PLC Power-Off

The root cause is not a fault in the drive — it is the absence of a designed transition from REMOTE (fieldbus) to LOCAL (TM31/operator panel) when the master drops. There are three contributing conditions:

1. Single command source. The drive is configured for a single active CDS in which control words (STW1) and setpoints (HSW) come exclusively from PROFIBUS. When the master is gone, those signals go to zero, the drive's source-of-control logic interprets the zero as a commanded stop, and F01910 documents the loss-of-setpoint event.
2. No fallback CDS. A second CDS exists in the project but is not wired to a fallback trigger. The drive cannot switch sources automatically when the bus fails.
3. Operator station inactive. The TM31 or AOP30 is wired but not selected as the active control source for the duration of the failure.

The corrective actions in the next four sections resolve these three conditions individually or in combination.

4. Solution A — Suppress F01910 via Parameter p2118 / p2119

This is the simplest fix and is appropriate when the PLC shutdown is a planned, supervised event and a hard-wired fallback already exists. The SINAMICS fault-handling mechanism allows the user to reclassify a fault as an alarm or to suppress it entirely.

4.1 Procedure on a G150 with a CU320-2 DP

1. Open Starter or the integrated Web Server of the drive and go online to the G150.
2. Navigate to Expert list → Messages / Monitoring → Faults and alarms.
3. Set p2118[0] = 1910 (write the fault number into the suppression index).
4. Set p2119[0] = 1 (mode: suppress the fault entirely).
5. Save the parameters to the non-volatile card with Copy RAM to ROM (or p0977 = 1).
6. Cold-restart the CU320 to confirm the change persists.

The p2118 / p2119 mechanism provides 16 index slots (0 to 15). Slot 0 is consumed by the F01910 reclassification; slots 1 to 15 remain free for additional messages (commonly F08501 to F08505 for PROFIBUS diagnostics and A01910 if the user wants a logged event instead of silence).

4.2 Allowed values for p2119

5. Solution B — Automatic CDS Switching via p810 and r2043.0

Solution A hides the symptom; Solution B fixes the cause by switching the drive from PROFIBUS control to TM31 control at the moment the bus fails. The switch is implemented with a BICO connection from the setpoint-failure status bit to the CDS-selection input.

5.1 Signal Chain

The required chain is:

r2043.0 (setpoint failure) → invert via free function block → p810 (CDS bit 0 source)

r2043.0 is active high on bus failure, but p810 expects 1 to mean "select CDS1" (the LOCAL set) and 0 to mean "select CDS0" (the REMOTE set). To select the LOCAL CDS during failure, the signal must be inverted using one of the SINAMICS free function blocks (FFBs).

5.2 Parameter Configuration

1. Confirm that CDS0 (PROFIBUS / REMOTE) and CDS1 (TM31 / LOCAL) are configured in the project with their respective setpoint and control-word sources.
2. Set p810 = 0 temporarily to disconnect the default source.
3. Open the free-function-block editor in Starter (under Technology → Free Blocks or via the parameter tree at p20000+). Configure one NOT-element:

NOT1.in = r2043.0
NOT1.out = p0810 (CDS0/1 selector)

4. Alternatively, without FFBs, use p810 directly and invert the CDS bit meaning by swapping which CDS is "PLC" and which is "LOCAL" in your project — this is cleaner if you can assign CDS1 to PROFIBUS and CDS0 to TM31, in which case p810 = r2043.0 directly selects the LOCAL CDS on failure.
5. Save with Copy RAM to ROM and re-cycle the CU320.

5.3 Expected Behaviour

• PLC online, telegrams flowing: r2043.0 = 0 → CDS0 (PROFIBUS) is active.
• PLC off: r2043.0 = 1 after p2040 ms → CDS1 (TM31) becomes active automatically. Drive continues to run on TM31 setpoints and remains in remote of the cabinet, but reports from the bus are absent.
• PLC returns: telegrams resume → r2043.0 = 0 → CDS0 is restored. The PLC must re-take control through its normal handshake; do not assume the drive will perform an instant bumpless transfer.

6. Solution C — PLC-Side D_ACT_DP / SFC12

If the PLC can be reprogrammed, the cleanest approach is to have the PLC deactivate the drive's DP slave slot before the PLC powers off. This prevents the drive from ever seeing a telegram gap because the PLC announces its intent to drop the slave cleanly.

6.1 S7-300 / S7-400 with SIMATIC Manager

Call SFC12 "D_ACT_DP" from the OB1 / OB82 / OB100 hierarchy with the slave's PROFIBUS address and a mode value:

CALL SFC12
  REQ   := TRUE
  MODE  := 2 (deactivate)
  LADDR  := W#16#3FF (diagnostic address of the G150 DP slave)

Issue MODE = 1 (activate) before resuming normal cyclic exchange.

6.2 S7-1200 with TIA Portal V12 (FW V3.0)

The S7-1200 supports the D_ACT_DP instruction natively. Insert it from the Communication palette. Configure:

• REQ: trigger bit (rising edge starts the action)
• MODE: 1 = activate, 2 = deactivate
• LADDR: HW identifier of the slave — obtain it from the device configuration (system constants; on TIA V12 the value is generated automatically and is typically HW_DeviceConfig_...).

6.3 Caveat on PLC Power-Off

If the PLC is hard-powered-off without running the deactivation sequence, SFC12 / D_ACT_DP cannot execute and the drive still sees the telegram gap. The instruction is therefore only effective for orderly shutdowns triggered by a software routine (HMI stop button, routine power-down). For a hard power failure of the PLC, combine SFC12 with Solution A or B.

7. Solution D — Physical LOCAL / REMOTE Switch on TM31

Where the PLC is shared with a maintenance operator, the most robust answer is hardware: a LOCAL / REMOTE selector wired into the TM31 digital inputs, with the drive set up to accept commands from TM31 in LOCAL and from PROFIBUS in REMOTE.

7.1 Wiring Pattern

• Selector switch with make-before-break (MBB) contacts, not standard break-before-make.
• Wire the LOCAL/REMOTE bit to a TM31 digital input (e.g. DI0 of the TM31) and route it via BICO to p0810 (CDS selection) or to p0840 (ON/OFF1 source override) so the drive commands follow the switch position rather than the bus state.

Standard break-before-make contacts momentarily open both paths during transition. The drive interprets the gap as a coast command, then re-engages, which trips F01910 and any F08501 / F08502 PROFIBUS link alarms. Use MBB contacts (e.g. Eaton M22 series with M22-K20 MBB cam or equivalent) or interlock the switch position with a small PLC that holds the previous state for 100 ms during transition.

8. Consolidated Configuration Matrix

9. Verification Procedure

After applying any combination of the above, validate the change using the following sequence:

1. Static check. With the drive stopped, read r2043.0 in Starter online. Confirm bit is 0 when the PLC is in RUN, 1 when the PLC is off.
2. Active-0 verification. Run the drive at 30 % speed with PLC in RUN. Read r0054 (active CDS) and confirm CDS0.
3. Power-down simulation. Toggle the PLC power supply off. Confirm:
   • F01910 does not appear in the fault buffer, or appears and is classified as an alarm only.
   • r0054 switches to CDS1 within (p2040 + 50 ms).
   • The drive continues to follow the TM31 reference.
4. Restart. Restore PLC power, wait for PROFIBUS to come up. Confirm the drive returns to CDS0 once r2043.0 drops. If the PLC handshake is required (typical for PROFIsafe or drive-based word-bits to gate setpoint acceptance), restart the PLC's cyclic block from a cold-init OB100.
5. Parameter persistence. Cycle control voltage to the CU320 and verify that p2118 / p2119 / p810 retain their setpoints from the non-volatile card.

10. Edge Cases and Field-Proven Caveats

• Multiple drives on one DP segment. If several G150 share a segment with one PLC, deactivating one slave via D_ACT_DP does not disturb the others. Suppressing F01910 on one drive affects only that drive.
• PROFINET substitution. On a CU320-2 PN (PROFINET), the same logic applies with r2043.0 mapped from PROFINET diagnostics. The parameters p2118 / p2119 / p810 are identical.
• PROFIsafe. If PROFIsafe is active (F-CPU with PROFIsafe telegram 30), F01910 must be handled differently because the safety channel will demand a safe stop. Suppressing F01910 in this context is not permitted.
• Operator panel AOP30. If an AOP30 is fitted, LOCAL/REMOTE switching can be performed in software via the panel's key-switch input, which removes the need for the MBB contact pattern.
• Alarm A01910. After reclassifying the fault as an alarm via p2119 = 2, message A01910 is written to the alarm history. Use r2122 to read and clear if required.
• Time-out tuning. If the process is sensitive to the 200 ms default, lower p2040 to 50 ms (the minimum PROFIBUS telegram cycle is 1 ms, but Siemens recommends a minimum of 50 ms for stable detection). Do not raise p2040 to mask F01910 — that is a band-aid that hides real failures.

11. Parameter Quick Reference

12. Recommended Approach

For most retrofit cases, deploy Solutions A and B together: suppress F01910 (or convert to A01910 for logging) and auto-switch CDS via p810 with the inverted r2043.0. This combination lets the drive transition cleanly to TM31 / LOCAL on PLC power-off and back to PLC on return, while still recording the event. Add Solution C only if the PLC program is well-structured around D_ACT_DP, and add Solution D when maintenance operators must take over in flight.

For greenfield installations, design the application with two CDS from the start, wire a hard-wired MBB LOCAL/REMOTE selector on the TM31 as the primary fallback, and use PROFIBUS only as the normal-mode REMOTE source. F01910 then becomes a true fault (desirable) that the hard-wired fallback prevents by removing the bus as the active source.

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