What it means
A01971 is the alarm CBExx: maximum number of controllers exceeded
. The drive raises it when a controller attempts to establish a connection to the drive and, as a consequence, the permitted number of PROFINET connections would be exceeded. No acknowledgement is required: the alarm is automatically withdrawn after approx. 30 seconds.
Why it appears
- A controller attempts to establish a connection to the drive, and this connection would exceed the permitted number of PROFINET connections.
What to check
- Check the configuration of the PROFINET controllers — the connections a controller establishes to the drive must stay within the permitted number.
Reading the message value
- The drive reports the message value as Info 1 (%1) and Info 2 (%2); the same information is coded in the alarm value r2124, which must be interpreted as hexadecimal: yyyyxxxx hex, where yyyy is Info 1 and xxxx is Info 2.
- Info 1 = 0: the number of RT connections was exceeded.
- Info 1 > 0: the number of IRT connections was exceeded.
- Info 2: the permitted number of connections.
Parameters the manual names
- r2124 — alarm value: for this alarm, read it as a hexadecimal yyyyxxxx value to see whether RT connections (Info 1 = 0) or IRT connections (Info 1 > 0) were exceeded, and what the permitted number of connections (Info 2) is.
Acknowledging and restarting
This alarm needs no acknowledgement — the drive withdraws it automatically after approx. 30 seconds. It reappears as long as controllers keep attempting connections beyond the permitted number of PROFINET connections, so check the configuration of the PROFINET controllers.
The same on every family
Every manual that describes A01971 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Error in the parameterization / configuration / commissioning procedure (18) | None | SINAMICS S120, S150 List Manual · p. 2721 |
The drives this code lives on
A01971 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A01971 mean on a SINAMICS S120 or S150?
The drive raises A01971 when a controller attempts to establish a connection to the drive and this would exceed the permitted number of PROFINET connections. It is the alarm the manual titles CBExx: maximum number of controllers exceeded.
How do I clear alarm A01971?
You do not have to acknowledge anything — the alarm is automatically withdrawn after approx. 30 seconds. If it keeps coming back, check the configuration of the PROFINET controllers.
What does the alarm value r2124 tell me for A01971?
Read r2124 as a hexadecimal yyyyxxxx value: yyyy is Info 1 and xxxx is Info 2. Info 1 = 0 means the number of RT connections was exceeded, Info 1 > 0 means the number of IRT connections was exceeded, and Info 2 is the permitted number of connections.
Is A01971 a fault or an alarm?
It is an alarm, not a fault. It requires no acknowledgement and is automatically withdrawn after approx. 30 seconds.
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