What it means
The manuals list this message as VSM: Unknown alarm
: the Voltage Sensing Module (VSM) has reported an alarm that the Control Unit firmware cannot interpret. According to the manual, this can occur when the firmware on the VSM is more recent than the firmware on the Control Unit. The number of the unknown alarm is stored in r2124, interpreted as a decimal number. Depending on how the drive is configured, the same condition can also be issued as a fault (F) or with no reaction (N).
Why it appears
- The VSM has raised an alarm that the Control Unit firmware cannot interpret.
- The firmware on the VSM is more recent than the firmware on the Control Unit.
What to check
- Read the alarm value from r2124 — interpreted as a decimal number it is the number of the alarm the VSM raised.
- Remedy the firmware mismatch: either replace the firmware on the VSM by an older firmware version (r0148 shows the firmware version on the module) or upgrade the firmware on the Control Unit (r0018 shows the firmware version there).
- If required, read about the significance of this new alarm in a more recent description of the Control Unit.
Reading the message value
The message value is shown as New message: %1
. The manual decodes the value as follows:
- Alarm value (r2124, interpret decimal): alarm number — the number of the unknown alarm the VSM reported.
Parameters the manual names
- r2124 (alarm value) — read as a decimal number, it tells you which alarm the VSM reported.
- r0148 (Sensor Module firmware version, SM FW version) — shows the firmware version on the Voltage Sensing Module before you replace it with an older one.
- r0018 (Control Unit firmware version, CU FW version) — shows the firmware version of the Control Unit when you decide to upgrade it.
Acknowledging and restarting
This message does not stop the drive, and as an alarm it requires no acknowledgment. If the condition is issued as a fault (F), it is acknowledged immediately — a POWER ON acknowledgment is also possible; with no reaction (N), there is nothing to acknowledge. The cause is removed by the remedy above: an older firmware on the VSM or a newer firmware on the Control Unit.
What differs between the drive families
Straight from the manuals' own fields — A34999 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | — | — | Infeed faulted (13) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3196 |
| G130, G150 | NONE | NONE | Infeed faulted (13) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1866 |
The drives this code lives on
A34999 is described for G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does A34999 mean on a SINAMICS drive?
The Voltage Sensing Module (VSM) has reported an alarm that the Control Unit firmware cannot interpret. The manual explains that this can occur when the firmware on the VSM is more recent than the firmware on the Control Unit.
How do I fix alarm A34999?
Read the alarm number from r2124 (interpreted as a decimal number), then either replace the firmware on the VSM with an older version (r0148 shows the module version) or upgrade the Control Unit firmware (r0018). The significance of the new alarm can be read in a more recent description of the Control Unit.
Does A34999 stop the drive or need an acknowledgment?
The message triggers no stop response. As an alarm it needs no acknowledgment; if it is issued as a fault it is acknowledged immediately, with POWER ON as an alternative.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the A34xxx group · SINAMICS manuals · Siemens manuals