BGS2T cannot connect to gateway | Telit Cinterion IoT Developer Community
November 22, 2017 - 11:16am, 2088 views
I am trying to connect to a remote gateway (a WTX16.GSM ***) with our BGS2T.
The modem can receive and make voice calls (tested with PuTTY), but when I dial the gateway number I always get a "no carrier" response. The associated error is +CEER: 8,21,0
As far as I can tell, the operator has activated data calls on the SIM.
I am sure the gateway is properly configured and can send data, therefore the problem must be on my side.
The following is the result of AT&V command
E1 Q0 V1 X3 &C1 &D0 &S0 \Q0
S0:001 S3:013 S4:010 S5:008 S6:000 S7:060 S8:000 S10:002 S18:000
+COPS: 0,0,"I TIM"
Any help or suggestion would be really appreciated.
Is it a CSD call that you attempt to establish?
What interface are you using?
Maybe CBST setting is not supported.
Please paste the log.
thanks for your support. I am way out of my depth with this kind of modem calls, so bear with me if I misunderstood your questions.
Well, I don't know. I assume my modem should perform a voice call first, and then wait for a data call from the gateway. I have been able to access the gateway, and I confirm that the voice call is received. After two rings, however, the gateway hangs up and I receive the "no carrier" message on the terminal. The led on the gateway then stays on for some seconds, as if trying to call the modem, but I receive no further message on the terminal. If this can be of any help, I see "+CRING: VOICE" when calling the modem from a mobile.
PuTTY and ACS26. The latter does not provide any helpful message, this is the log:
I'm not sure of what you mean here. Could you elaborate a little on that?
Can you paste a log with AT commands to show what exactly you do with BGS2T module and where the problem occurs?
Are you developing some solution with BGS2T module or you are using a ready solution? Are you using a PC program or some device to connect to BGS2T?
Please write about the solution - how it is supposed to work - you establish a voice call to the gateway and the gateway is supposed to reject it and make a data call to your module? As I understand the gateway is supposed to transmit some data so it probably accepts or establishes a data calls only, not voice calls.
My question was if this was supposed to be CSD (circuit-switched data call: https://en.wikipedia.org/wiki/General_Packet_Radio_Service ) or GPRS (General Packet Radio Service: https://en.wikipedia.org/wiki/General_Packet_Radio_Service ).
CSD is not supported by all mobile network operators as it is an old technology. With CBST command you configure the data rate for the transmission. Not all rates are supported by particular operators.
Probably the WTX16.GSM *** uses CSD protocol. It is a rather old device from 2008-2009 when GPRS was just brand new. That is why I believe that this unit is using CSD.
If you use PuTTY, you can give the following commands when calling to the WTX16.GSM ***:
AYD12345678 -number directly written after ATD, no ";" otherwise you will get a voice call
If the modem calls you, you will get "+CRING: REL ASYNC", instead of "+CRING: VOICE" that is received using a mobile phone.
On the PuTTY, when WTX16.GSM *** calls you, it shows "+CRING: REL ASYNC". Answer "ATA".
Then you will get "CONNECT 9600/RLP" and the connection is established.
In order to make the CSD call work best, some initialisation settings for the BGS2T are required:
AT\Q3 hardware flow control
AT+CSNS=4 calls recognized as data calls
ATX4 dial tone and busy activated
ATS0=3 automatic answering after three rings
ATS7=60 timeout of 60 seconds to wait for the connection completion
ATS10=10 data carrier loss disconnect timeout 1 second
AT^SCFG="URC/Datamode/Ringline","on" URC indication by RING-line
AT+CBST=7 9600 bps V.32 or AT+CBST=71 9600 bps V.110 (sometimes works better)
AT+CRLP=61,61,78,6 set radio link parameters (default)
ATV0 short result code format (optional)
AT+CR=0 disable service reporting (optional)
AT%W store above to the BGS2T flash memory
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