EHS6 network scan fails | Telit Cinterion IoT Developer Community
November 28, 2017 - 4:03pm, 2634 views
Hi,
I'm having troubles in getting full network scan results successfully with my EHS6.
What I do:
AT^SCFG has "Radio/Band","511"
AT+CREG=2 // to get CREG info indications
AT+CMEE=2 // for extended error codes
AT+COPS=2 // to deregister from network
AT^snmon="INS",2 // to scan defined radio bands
and the result is list of values from rb 1 and then ERROR
^SNMON: "INS",0,1,0,"1088","0168","24412",7,23,"-68",1
..42 rows of results..
^SNMON: "INS",0,1,0,"0758","100F","24491",65,7,"-99",1
ERROR
The error is always printed after 40-45 seconds since start of scan. Scan seems to return duplicate values (rows).
If I narrow down the searched radio bands (for example to "17") then it is able to give results from the single radio band (rb 16 in this example) and ends with "OK". But only if it takes less than 40 seconds. Sometimes it also gives error +CME ERROR: operation not allowed. Output of ^SMONI is ^SMONI: 2G,SEARCH,SEARCH even after search so not sure if it performs something in the background or whether that is just a default output in deregistered state.
I have tested with both internationally roaming SIM and non-roaming SIM (to rule out if it would perform some internal scan due to roaming). There shouldnt be any other activity on the AT command ports. This is Linux system and I have tried both /dev/ttyACM0 and /dev/ttyS2 ports. I'm not interrupting the command by pressing any key on terminal. No Java applets installed except the default one from Gemalto.
ATI1 gives version:
Cinterion
EHS6
REVISION 03.001
A-REVISION 00.000.31
and I have also tested with A-REVISION 00.000.55
Can you please help me on this issue. Thanks!
Hello,
I have tested this with A-REVISION 00.000.55 on Windows. In my case there was always OK in the end, the complete scan was taking between 1 and 2 minutes and there was less then 40 lines.
Maybe your system sends something that breaks the command. Or it is also written in the document that the AT^SNMON="INS" command may be aborted internally by any other network related activity that interferes with the network scan.
Regards,
Bartłomiej
Hi,
I understand that in connected mode device wouldnt have time-window to search network. But this is while in deregistered mode, it should stay in limited service somewhere and have plenty of time to perform search.
Is there something I could check which operation or internal activity could cause this?
I tried as a workaround to limit searched radio bands but for example "Radio/Band","18" causes it to print
^SNMON: "INS",0,1
^SNMON: "INS",0,2
and then immediately gives up.
Also tried to force it to 3G by ^sxrat=2,2 and then try to search only 3G bands (just to see whether it is 2G search that causes problems) but same results, 40 sec and CME Error:
^SNMON: "INS",0,1
^SNMON: "INS",0,2
^SNMON: "INS",0,4
^SNMON: "INS",0,8
^SNMON: "INS",0,16,2,"0002A98B","138A","24491",10812,69,"-52",313
^SNMON: "INS",0,16,2,"0B00A007","138A","24491",10837,67,"-54",313
^SNMON: "INS",0,16,2,"0066D2A4","0014","24412",10737,37,"-84",155
^SNMON: "INS",0,16,2,"0020A576","5A00","24405",10588,35,"-86",380
^SNMON: "INS",0,16,2,"00203375","5A00","24405",10563,32,"-89",425
^SNMON: "INS",0,16,2,"0020A576","5A00","24491",10787,35,"-86",81
+CME ERROR: operation not allowed
Hello,
It's strange that the command returns error after 40 seconds while my module was able to scan for more than one minute and always returned OK in the end. So maybe it has something to do with your networks around. Maybe you could test it in some other place? But still I think that you could also try this with Windows OS. And please use A-REVISION 00.000.55 to be sure that you test with the latest software.
There's only one difference - in your case there was over 40 lines which I was not able to reproduce in my place.
Interesting is that the result was +CME ERROR: operation not allowed - that could suggest that the module is in a state when this operation cannot be performed or continued. There's the same result if you send this command while the module is registered to the network.
This command should work even without SIM card.
Regards,
Bartłomiej
Hi,
I found the solution. When opening the modem /dev/ttyACM0 I need to remove ECHO parameter from termios/c_lflag. After that 100% success rate. I just dont understand how this could affect it. Could you ask from the R&D if they have any ideas what is happening when this flag is enabled that could interfere with the scan process.
Hello,
Thank you for this information. We haven't heared of such thing so far.
So it seems that the problem was in the terminal program or OS.
As the module throws error in the middle of the scan because of this setting and there is always the same delay I think that the only possibility is that the terminal or OS sends something to the module or changes some line state. The only way to find it might be tracing on the hardware interface.
Regards,
Bartłomiej