FCM datahandler failure after certain tries


I’m opening FCM data connection over UART1 to a serial device and for every command sent by fcmSendData, the datahandler will be called to return the response.

For the first six calls to fcmSendData(), a corresponding response is returned by FCM datahandler. But after that, the datahandler was never called.
We probed the comm line and confirmed the data sent by fcmSendData and there’s response data coming in to WMP, but the datahandler never caught that response.

Has anybody seen this problem?


Hello Aberk,
I haven’t this problem and I am not an expert, but according to the application note WM_ASW_OAT_APN_022-001 (P_Using_FCM_flow_in_an_OpenAT_application.pdf), there are only 5 credits for sending data, that is 5 buffers. Maybe you are sending too much data without waiting for ADL_FCM_EVENT_MEM_RELEASE or maybe that by unsubscribing before receiving this event causes the ADL to retain the buffer and going out of buffer at the sixth time.
Hope this helps.

best regards

Massimiliano Pagani

I realized that my data handler was not releasing credits b/c I was not returning true, so the 120 byte UART buffer was filling up. I dont know why this problem didnt happen on our dev board and only cam about on the final product.