Resolving TIA Portal V15.1 Download Error with SINAMICS V90 A1932

Problem Summary

An "Error downloading to device" dialog appears in TIA Portal V15.1 when an engineer attempts to load the offline project into a SIMATIC S7-1500 CPU 1511T-1 PN that controls one or more SINAMICS V90 PN servo drives over PROFINET IRT. Concurrently, at least one V90 PN reports alarm A1932 on its basic operator panel (BOP) display. The drive alarm is the key diagnostic clue: it indicates that Dynamic Servo Control (DSC) is enabled in the configured PROFIdrive telegram, but either the PROFINET IRT clock synchronization has not been established, or the controller-to-drive sign-of-life counter is not being received inside the tolerance window defined by drive parameter p2042.

Although the dialog message targets the PLC, the underlying cause is in the network and drive configuration. Once the clock-synchronous relationship between the IO controller and the IO device is established, the drive alarm clears and the project download completes successfully.

Affected Hardware and Software

The following components and versions are typically involved. Verify each item against the actual installed hardware before applying the procedure.

Refer to the SINAMICS V90 Operating Instructions for the firmware version and PROFINET IRT capability of the installed drive. Refer to the SIMATIC S7-1500 System Manual for the IRT and sync-domain capabilities of the S7-1500 CPU family.

Alarm A1932 and Dynamic Servo Control (DSC) Background

Alarm A1932 is documented in the SINAMICS V90 Operating Instructions and indicates "DSC clock-cycle synchronous sign-of-life missing." The drive has detected that the IO controller has configured DSC in the active PROFIdrive telegram, but the sign-of-life counter coming from the controller is either absent, frozen, or out of the valid range. In some configurations the same root cause appears as fault F01932 (a trip) rather than alarm A1932 (a warning), depending on the value of drive parameter p2042.

DSC (Dynamic Servo Control) is a position-control topology in which the position controller runs inside the drive and the velocity loop is closed in the drive as well. The IO controller only issues the setpoint with one bus-cycle delay. DSC demands the following preconditions:

• PROFINET IRT with a synchronous send clock shared by controller and drives
• Both controller and drive assigned as sync master / sync slave in the same sync domain
• A PROFIdrive telegram that supports DSC (e.g., Siemens telegram 5, 105, 7, 9, 110, 111)
• Continuous increment of the controller sign-of-life counter, received inside the configured number of sub-cycles

When any of these prerequisites is missing, the drive raises A1932 and disables the DSC path. The drive then operates in a fallback position-control mode (or, in the worst case, refuses to enable the servo) until the issue is corrected.

Root Cause: TIA Portal IO Consistency Check

TIA Portal performs an offline-to-online comparison before issuing the download. If a downstream PROFINET device is configured for IRT in the offline project but the real network cannot establish IRT — for example, because the drive is in alarm state and not yet in cyclic data exchange — the consistency check detects a "PROFINET interface configuration error" and aborts the download with the generic message "Error downloading to device — online configuration differs from offline configuration." This is the message shown to the engineer.

The V90 alarm A1932 is the symptom that proves the network is not synchronized. Without the sync relationship, the drive never increments its sign-of-life counter and never moves from the pre-operational state to the cyclic-data-exchange state. Until the drive reaches cyclic data exchange, the S7-1500 cannot complete the IO consistency check, and TIA Portal refuses to commit the download.

The root cause is therefore a network/clock-synchronization problem, not a corrupted project or a firmware mismatch. The fix is to:

1. Configure PROFINET IRT in the project, including sync domain and topology.
2. Select a DSC-capable PROFIdrive telegram for the V90.
3. Place the CPU in STOP mode.
4. Reload the project.

Prerequisites

Before starting the procedure, confirm the following:

• TIA Portal V15.1 with Startdrive option installed (license 6AV2100-0AA05-0AA5)
• CPU 1511T-1 PN online via the configured PROFINET interface (port X1)
• All V90 PN drives online with the correct IP address and PROFINET device name assigned (e.g., "v90-1", "v90-2")
• Topology editor populated with port-to-port interconnections between the controller, any switches, and the V90 drives
• Sync domain defined with the controller designated as sync master and the drives as sync slaves
• V90 firmware version that supports PROFINET IRT (refer to the SINAMICS V90 Operating Instructions for the installed firmware revision)
• Online access from the engineering PC to the S7-1500 PROFINET subnet

Step-by-Step Resolution

Step 1 — Place the CPU in STOP

Before any further action, place the CPU in STOP mode. This stops the cyclic IO exchange, allowing the offline project to be loaded without conflict. From the project tree, right-click the CPU > "Online & Diagnostics" > "Operating Mode" > "STOP". Alternatively, turn the mode switch on the CPU front panel to STOP. Confirm the RUN/STOP LED is yellow and the ERROR LED is off.

Step 2 — Verify the PROFIdrive Telegram in Startdrive

Open the V90 device configuration in Startdrive. Under "PROFIdrive telegram" select a telegram that supports DSC:

• Telegram 5 — 32-bit position + 32-bit velocity, DSC-capable
• Telegram 105 — extension of telegram 5 with second encoder and DSC
• Telegram 9 — 32-bit position with DSC

Avoid telegrams 1, 2, 3 (standard telegrams without DSC) if the S7-1500T motion technology objects (TO_PositioningAxis, TO_SynchronousAxis) reference the drive with DSC enabled. Confirm by reading drive parameter p0922 on the BOP after the project download.

Step 3 — Configure the PROFINET IRT Sync Domain

Open "Devices & Networks" and select the PROFINET subnet. In the inspector window, navigate to "PROFINET interface > Real time settings > Synchronization".

1. Tick "IRT" for both the IO controller and each V90 IO device.
2. Select "Sync master and sync slave" for the controller and "Sync slave" for each drive.
3. Set the send clock to a value the V90 supports (1 ms, 2 ms, or 4 ms). For multi-axis motion applications, 1 ms is typical.
4. Set the reduction ratio so that the application cycle is a whole multiple of the send clock. The MC-Servo task in the S7-1500T typically runs at 1 ms; with a 1 ms send clock, the reduction ratio is 1:1.

Step 4 — Wire the Topology Editor

Open the topology view and create the port-to-port connections between the controller, the switches (if any), and the V90 drives. PROFINET IRT requires a defined topology for the sync-forwarding path. Unconnected or mismatched ports degrade IRT to RT, which the drive interprets as "clock synchronization lost" and raises A1932. The CPU 1511T-1 PN has two PROFINET interfaces; the second port can be used for a line topology with port 2 of the first V90 looping to the second drive.

Step 5 — Enable the Sign-of-Life Counter in the Drive

The sign-of-life counter is enabled by default in the V90 when DSC is selected, but the monitoring tolerance must be set. In the V90 parameter list (BOP or Startdrive parameter view):

For the full parameter list, refer to the SINAMICS V90 Operating Instructions parameter chapter.

Step 6 — Compile and Download

1. Right-click the S7-1500 CPU in the project tree > "Compile > Hardware (rebuild all)".
2. Select the CPU > "Download to device > Hardware and software (only changes)".
3. In the download dialog, click "Start search" to identify the CPU.
4. Confirm the target CPU. TIA Portal may show a warning that the IO device is in a non-cyclic state. Tick "Continue anyway" only after the sync configuration has been corrected.
5. Click "Load".

Step 7 — Restart and Verify Cyclic Exchange

After the download completes, switch the CPU back to RUN. Monitor the V90 BOP or Startdrive online diagnostics. The alarm A1932 should clear within one second. The diagnostic LEDs on the V90 (RDY green, COM green) should show steady green. The PROFINET LED on the CPU should show steady green.

Verification

1. In TIA Portal, open "Online & Diagnostics" for the V90. The "Diagnostic buffer" should show no A1932 entries after the configuration change.
2. In the S7-1500T technology objects, open the axis "Diagnostics" view. The "Status" field should report "Cyclic data exchange OK".
3. Execute a small motion test (e.g., MC_MoveVelocity with 100 mm/s, distance 10 mm) to confirm that the drive follows the setpoint.
4. Check the V90 BOP display. It should show the operating state (e.g., "S" for Servo ON) without any alarm code.
5. Read the PROFINET diagnostics via the V90 parameter r2053[0..15] and r2054[0..15] (process data and status words) to confirm the sign-of-life counter is incrementing on every cycle.

Drive Parameter Reference for V90 PN with DSC

For the complete V90 parameter list, refer to the SINAMICS V90 Operating Instructions parameter chapter.

Troubleshooting Matrix

Commissioning Notes

When using two V90 PN drives on the same S7-1500T, ensure that both drives are in the same PROFINET sync domain and that the topology is defined for the path between the controller and each drive. IRT performance degrades if any unmanaged switch is in the path. Use only PROFINET-conformant switches (e.g., SCALANCE XC-200) or wire the drives in a line topology directly from the controller's PROFINET ports. The CPU 1511T-1 PN has two PROFINET interfaces; the second port can be used for line topology with port 2 of the first drive looping to the second.

If the project still fails to download after the clock synchronization is verified, the next step is to delete the V90 device name in TIA Portal and reassign it via "Online > Assign PROFINET device name". This forces the drive to re-read the configuration and re-enter the cyclic data exchange state.

For the S7-1500T motion technology objects (TO_PositioningAxis, TO_SynchronousAxis, TO_ExternalEncoder), confirm that "Enable DSC" is selected in the axis configuration. DSC is selected by default for S7-1500T axes but may have been disabled by the engineer. If DSC is disabled in the TO but enabled in the drive telegram, the drive still expects a sign-of-life and raises A1932.

The MC-Servo task in the S7-1500T should be set to 1 ms when the send clock is 1 ms, or to 2 ms / 4 ms when the send clock matches. A mismatch between the application cycle and the PROFINET send clock will cause the controller to issue the sign-of-life counter at the wrong rate, and the drive will raise A1932 after one tolerance cycle.

Frequently Asked Questions