FCM subscription failure



I’m working with Q24PL001, and the UART1 is set by default to AT commands (UART2 is not connected). I do connect, send and recieve data using GPRS bearer with HTTP protocol, and I need to check changes on a web page lower than 1Kb, but after sending about 10-20 times GET requests with intervals of 2 or 3 secs, I get the FCM subscription failure error… what can I do about it? It should be a buffer full problem like other topic said? How can I fix it? I’m closing the bearer connection but the problems persist.

I’m not using development software most of you guys use, I’m just sending AT commands and opening the WIPstack, and the manuals of the product I got say anyting about fixing or changing FCM parameters, or reading the status of the WIPstack or FCM.

Simply letting me know why this problem appers will help me to solve the problem, or if you have a document I can read… so every comment will be help.

Thank in advance,


What “FCM subscription failure error” :question:

You need to show the sequence of commands you’re sending, and the responses you’re getting - includign the error.


Thanks awneil for trying to help me.

Like I said before is that most of you develop software directly to Wavecom processor, instead of me, I’m making a simply development using WIPsoft or WIPstack API installed on wavecom processor, and connecting the modem to PC and sending the AT commands defined by WIP (Wavecom Internet Protocol) stack.

Some of AT commands and the sequence I send is:

AT+WOPEN=1 (open WIPstack)
OK (response)
AT+WIPCFG=1 (start WIPstack)
OK (response)
AT+WIPBR=1,6 (use GPRS bearer)
OK (response)
AT+WIPBR=2,6,11,“APN” (APN)
OK (response)
AT+WIPBR=2,6,0,"" (USER… no user)
OK (response)
AT+WIPBR=2,6,1,"" (PASS… no password)
OK (response)
AT+WIPBR=4,6,0 (start GPRS)
OK (response)
AT+WIPCREATE=5,1,“http://webpage.com”,“80” (create HTTP connection on port 80)
OK (response)
+WIPREADY: 5,1 (response)
AT+WIPFILE=5,1,1,“http://webpage.com” (GET request for HTTP, almost 125bytes command length)

Here I get the html web page less than 1kb, maybe 400 bytes. But when sending for intervals of 2 or 3 secs the GET request for about 10-20 times it get stock and send me this:

+CME ERROR: 846 (which means “FCM subscription failure error”)

Thats the answer for your question awneil, I found out that FCM means Flow Control Manager, and the only place I found about this is here in this forum. I read all the manuals of WIPstack I found with all the possible AT commands and the error only is mentioned but not how to fix it, or even why this happend.

Some thread I read before was related of making subscription to UART1 or UART2, or some FCM error and talk about buffer memory full and everyone sugesst to release the buffer memory, or wait to buffer memory was empty. And I can’t do that… or I don’t know the AT “special” command to do that.

The only way out I found is to make the modem a software reset… but I loose about 60 secs for reconnection, and the interval of 2 or 3 secs, up to 10 secs is crucial for my application.

I hope I can explain my problem but most important is that you understand what’s happening becouse I don’t.

Thanks again,


The full description is:

So there is something going wrong internally within WIPSoft - and there’s nothing you can do about that. :frowning:

All the talk about UARTs and FCM is for people writing their own Open-AT applications; but you are using a ready-made application - WIPSoft.

So, unfortunately, you are stuck. :frowning:
I think you need to contact your Wavecom Distributor - maybe this is a known bug in WIPSoft…?


Sad to hear that… so I will have to make soft resets frecuently, it’s weird because I use some kind of visitor counter on the html, and everytime I use GET (long AT command I need) the counter increments… the thing is that I can’t recieve the html web page, it seems to be recieving buffer memory full.

I’m interested of starting my own Open AT application… and it’s very complete, not so easy but never impossible, and I understand I can use WIPsoft and others as a plug-in of my new application, very interesting.

Thanks for the advise… and thanks for your time and help.