RALRM SFB54 AINFO empty

Dear Community,

I'm developing a custom made block to read diagnostic info from Danfoss FC302 drive. To read diagnostic interrupt I'm using RALRM (SFB54).

AS input/output of RALRM I've the following data:

- Mode : 1 To read all output Data

- Status : 16#0

- LEN : 0 (The length of the extracted AINFO)

I receive the data of TINFO (Destination area for OB start and management information) without problem, only AINFO is always empty with zeros as values.
I followed the documentation and it's pending on the called OB we receive AINFO, but I still have zeros in different OBs (55,56,57 and 82). I only receive TINFO data when an alarms happen and the called block is in OB82.

[Attached is] an extract of the block where I'm declaring AINFO and TINFO as static.

Ensure the Danfoss FC302 drive supports and is configured to send diagnostic interrupts. 
Verify OB82 is correctly set up in the PLC to handle diagnostic interrupts, along with OB55, OB56, and OB57.
Check the hardware configuration and confirm correct integration and mapping of AlarmCheckID.
In SFB54, set LEN > 0 to enable diagnostic data transfer into AINFO.
Set Mode = 1 in SFB54 to extract both TINFO and AINFO.
Ensure sAINFO and sTINFO structures are correctly defined with proper data types and memory.
Update the PLC firmware and install the latest PCS7 Update Collection (Ex. 912 UCxx).
If issues persist, contact Danfoss for support on diagnostic data compatibility with Siemens PLCs

Dear Techno_Sharva,

Thank you so much for your reply!
The Danfoss FC302 is configured to send diagnostic interrupt.
The PLC is also well configured to handle the diagnostic interrupt.
My problem was that I set the value of MLEN to zero following the documentation meaning having the maximum of data of AINFO, changing that value to the size of the sAINO struct size give the needed data in AINFO.
Thank you again for your collaboration.