What it means
A37801 is reported as “HF Damping Module: Sign-of-life missing”. Behind it stands a DRIVE-CLiQ communication error between the Control Unit and the HF Damping Module: the sign-of-life bit in the receive telegram is not set. Depending on the drive’s configuration, the same condition can also be output as fault F37801 or as a message with no reaction.
Why it appears
- There is a DRIVE-CLiQ communication error between the Control Unit and the HF Damping Module.
- Fault cause 10 (= 0A hex):
The sign-of-life bit in the receive telegram is not set.
What to check
- Read the message value in r2124 — or in r0949 if the condition was output as a fault. It is coded 0000yyxx hex, so yy gives the component number and xx the error cause, which identifies the component involved.
- Check the DRIVE-CLiQ connection between the Control Unit and the HF Damping Module.
- If the message persists, replace the component involved.
Reading the message value
- The manual prints the value as “Component number: %1, fault cause: %2”.
- The individual information is coded in the message value (r0949/r2124) as 0000yyxx hex: yy = component number, xx = error cause.
- For this code the error cause is 10 (= 0A hex): the sign-of-life bit in the receive telegram is not set.
Parameters the manual names
- r2124 (alarm value): while A37801 is active as an alarm, r2124 holds the coded message value 0000yyxx hex, from which you read the component number (yy) and the error cause (xx).
- r0949 (fault value): if the same condition is output as a fault instead, the identical coded value stands in r0949.
Acknowledging and restarting
As an alarm, A37801 takes no reaction and needs no acknowledgment — it is enough to repair the DRIVE-CLiQ connection or replace the affected component. If the drive is configured to output the same condition as fault F37801, the fault must be acknowledged immediately.
The same on every family
Every manual that describes A37801 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Internal (DRIVE-CLiQ) communication error (12) | None | SINAMICS S120, S150 List Manual · p. 3269 |
The drives this code lives on
A37801 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A37801 on a SINAMICS S120 mean?
The HF Damping Module reports a DRIVE-CLiQ communication error with the Control Unit: the sign-of-life bit in the receive telegram is not set (fault cause 10, = 0A hex).
How do I fix A37801?
Check the DRIVE-CLiQ connection between the Control Unit and the HF Damping Module, and replace the component involved if the message persists. The message value in r2124 (0000yyxx hex) tells you the component number.
Does A37801 have to be acknowledged?
No. As an alarm it needs no acknowledgment and the drive takes no reaction; only if it is output as fault F37801 must it be acknowledged immediately.
In which parameter can I read the message value of A37801?
In r2124 (alarm value) while the alarm is active; if the condition comes as a fault, the coded value is in r0949 (fault value). Both use the format 0000yyxx hex.
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 A37xxx group · SINAMICS manuals · Siemens manuals