Error message return code 104 in SM21 when receiving telegrams from automated picking machine

[mpecoraro]

Hi SAP Experts,

I am testing sending & receving telegramson a SAP S4 embeded EWM system. The system is sending telegrams to a automated picking machine (non-sap). They are connected by TCP IP connection with websockets and both servers are running on Linux. The websocket is connected to an ABAP push channel application. We are currently able to send telegrams to the server of the picking machine but cannot receive any telegrams.

Whenever the sap system sends a telegram to the picking machine and the picking machine sends back an acknoledgememnt the error messagethat is in SM21 is "Transaction canceled 00 001 ( Receive error with error text: ERROR-WEBSOCKET-WS_ MPI_ERROR (return code 104) )"

I performed another test where the automated picking machine would send a random message to the sap server (one where no warehouse order was created in SAP) and the error in SM21 was "Runtime error "ASSERTION_FAILED" occurred." Indicating that the data reached the application as the copde in the push chanel verifies if an order exists and then inserts into a telegram history table.

Can someone please help me with this problem?

Regards,

Marco

[syedkamran]

Is your TCP/IP RFC connection is working fine in your s/4 Hana system ?

[Daniil]

have you checked ST22 to see what is ASSERT dump about?

[mpecoraro]

Hi Daniil,

This is the error message in st22: WARNING => ThrtApcGetInbuf: MpiGetInbuf for mpi <****> failed (MPI_ESTALE: outdated MPI handle), return to caller [thrtApcHandl ***]

[Isaías]

Hello Marco,

This MPI_ESTALE message means that something went wrong on the work process that was handling the request, causing the MPI to be discarded and breaking the synchronization with the ICM.

Do you see anything that cold be related to this at the system log (transaction SM21)?

We would need to identify what was the work process, and then verify what happened with it.

Regards,

Isaías

[mpecoraro]

Hi Isaías,

In sm21 there's the below message

The transaction has been terminated. This may be caused by a termination message from the application (MESSAGE Axxx) or by an error detected by the SAP System due to which it makes no sense to proceed with the transaction. The actual reason for the termination is indicated by the T100 message and the parameters.

[mpecoraro · Accepted solution]

Hi,

The resolution for the above was to set the picking machine responses to telegrams from asychronous to synchronous. We also got the same issues when telegrams sent from the picking machine to SAP did not contain a line feed indicating to SAP that it was the end of the message.

Regards,

Marco

[mamartins]

Is that picking machine a SAP certified solution? https://www.sap.com/dmc/exp/2013_09_adpd/enEN/#/solutions

For integration scenarios like yours, usually a PI/PO system is involved, because is the SAP product to let SAP systems talk to non-SAP systems.

[mpecoraro]

Yes the connection is working fine in the TCP/IP RFC connection. I inserted a breakpoint in method "IF_APC_WSP_EXTENSION~ON_START" that initiating WebSocket connection setup in the abap push application and it was reached however, theres no data in the message. It seems the contents of the telegram are now not included.