What it means
A01925 reports a lost Modbus TCP link: the Ethernet connection between the drive and the Modbus controller has been interrupted. The drive classes the message as a communication error to the higher-level control system (9). The G130/G150 and S120/S150 manuals describe the message identically — the cause and the remedy are the same on every drive object, and no message value is supplied with the alarm. Depending on how the drive is configured, the same condition can also be output as a fault instead of an alarm.
Why it appears
- The Ethernet connection to the Modbus controller is interrupted. The manuals name this single cause for all drive objects — there are no component-specific variants.
What to check
- Re-establish the Ethernet connection to the Modbus controller.
- Activate the Modbus controller.
Acknowledging and restarting
The alarm needs no acknowledgement and the drive executes no automatic reaction to it: as soon as the Ethernet connection exists again and the Modbus controller is active, the message clears by itself. Only if the drive is configured to raise the same condition as a fault does an acknowledgement become necessary — and then IMMEDIATELY.
The same on every family
Every manual that describes A01925 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Communication error to the higher-level control system (9) | None | SINAMICS S120, S150 List Manual · p. 2716 |
| G130, G150 | NONE | NONE | Communication error to the higher-level control system (9) | None | SINAMICS G130, G150 List Manual · p. 1492 |
The drives this code lives on
A01925 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 alarm A01925 mean on a SINAMICS drive?
It reports that the Ethernet connection to the Modbus controller has been interrupted. The drive classifies the message as a communication error to the higher-level control system (9).
How do I clear A01925?
Establish the Ethernet connection to the Modbus controller again and activate the Modbus controller. As an alarm, the message then disappears without needing an acknowledgement.
Does A01925 stop the drive?
No. As an alarm the message triggers no automatic reaction from the drive; it only signals that the Modbus TCP connection is down.
Can A01925 also appear as a fault?
Yes — depending on the drive's configuration, the same condition can be output as a fault instead of an alarm. In the fault variant it must be acknowledged IMMEDIATELY.
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 A01xxx group · SINAMICS manuals · Siemens manuals