What it means
A01945 is an alarm from the PROFIBUS peer-to-peer communication: the connection to at least one Publisher has failed, so the drive no longer exchanges peer-to-peer data with that Publisher. The alarm itself triggers no automatic response from the drive. Which Publisher is affected is shown bit by bit in the alarm value r2124, using the Publisher addresses stored in r2077.
Why it appears
- During PROFIBUS peer-to-peer data transfer, the link to at least one Publisher has gone down.
What to check
- Identify the failed Publisher: read the alarm value r2124 as a binary number and take the address of the affected Publisher from r2077 at the same index — bit 0 belongs to the Publisher with the address in r2077[0], bit 15 to the Publisher with the address in r2077[15], and the bits in between follow the same pattern.
- Check the PROFIBUS cables.
- Carry out a first commissioning of the Publisher that has the failed connection.
Reading the message value
- The drive stores the alarm value in the message value as a binary number — the manual prints the placeholder as
Fault cause: %1 bin
; the value behind it is r2124, which the manual says to interpret binary. Bit 0 = 1: Publisher with address in r2077[0], connection failed.
Bit 15 = 1: Publisher with address in r2077[15], connection failed.
- The manual prints only the first and the last bit of this map; every bit between bit 0 and bit 15 follows the same pattern, so each bit marks the Publisher whose address is stored at the matching index of r2077.
Parameters the manual names
- r2124 (alarm value): read it as a binary number for this alarm — every bit set to 1 marks a Publisher whose connection has failed.
- r2077 (PROFIBUS diagnostics peer-to-peer data transfer addresses): holds the address of each Publisher; the position of the set bit in r2124 points to the entry belonging to the failed Publisher.
Acknowledging and restarting
No acknowledgement is required for this alarm. It clears itself once the cause is removed — after the PROFIBUS cabling has been repaired or the Publisher with the failed connection has been commissioned.
What differs between the drive families
Straight from the manuals' own fields — A01945 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| G130, G150 | NONE | NONE | Communication error to the higher-level control system (9) | None | SINAMICS G130, G150 List Manual · p. 1494 |
| S120, S150 | NONE | NONE | Communication error to the higher-level control system (9) | None | SINAMICS S120, S150 List Manual · p. 2718 |
| G120 | NONE | NONE | Communication error to the higher-level control system (9) | — | SINAMICS G120 · p. 861 |
| G120XA | NONE | NONE | — | — | SINAMICS G120XA PN converter · p. 1114 |
The drives this code lives on
A01945 is described for G120, G120XA, G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A01945 mean in SINAMICS?
It reports that the connection to at least one Publisher has failed during PROFIBUS peer-to-peer data transfer. The alarm value r2124, read as a binary number, shows which Publisher is affected.
How do I find the failed Publisher for A01945?
Interpret r2124 bit by bit: bit 0 set means the Publisher with the address in r2077[0] failed, bit 15 set means the Publisher with the address in r2077[15], and the bits in between follow the same pattern.
How do I fix alarm A01945?
Check the PROFIBUS cables first. If the connection is still down, carry out a first commissioning of the Publisher that has the failed connection.
Does A01945 need to be acknowledged?
No. The alarm clears itself once the connection to the affected Publisher is restored.
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