HL7800 Vodacom TCP Connection failure

IoT Modules HL78
1

I’m trying to test a TCP connection with the HL7800 modem using the HL78 Dev Kit. I am based in South Africa, using a Vodacom SIM which has data and is capable of SMS (my personal SIM). However, I am unable to successfully make a TCP connection and almost always receive +KTCP_NOTIF: 1,5 (TCP connection error) and sometimes +KTCP_NOTIF: 1,3. I think it might’ve worked once and I received +KTCP_IND:1,1 but I have not been able to replicate this after trying numerous times.

I believe this may either be a signal/coverage issue of NBIOT or I am simply not configuring the modem correctly. Would greatly appreciate anyone who can provide some incite as to which of the two it likely is! Thanks!

Here is a test terminal log:

ATI9
ATI9

HL7800.4.5.4
HL78xx.4.5.4.0.RK_02_01_02_00_101.20200722
2020/07/22 23:38:03
IMEI-SV:
Legato RTOS: 18.09.5.ALT1250.rc4 2020/05/29 19:39:14
atSwi: 35.00
UBOOT: 01.03
Apps: RKAPP_02_01_02_00_94__31f472b547df5417a8f942dd14d4c8cb9bf65395
MAC:
PHY: 0.0.232169
PMP: 234124
SBUB: 0
SBFW: 0
RPuK:
FPuK:
RBUB: 0
RBFW: 0

OK
AT+CFUN?
AT+CFUN?

+CFUN: 1

OK
AT+CPIN?
AT+CPIN?

+CPIN: READY

OK
AT+CNUM
AT+CNUM

OK
AT+KSRAT?
AT+KSRAT?

+KSRAT: 1

OK
AT&K3
AT&K3

OK
AT+KCNXCFG=1,“GPRS”,“lte.vodacom.za”
AT+KCNXCFG=1,“GPRS”,“lte.vodacom.za”

OK
AT+KTCPCFG=1,0,“www.google.com”,80
AT+KTCPCFG=1,0,“www.google.com”,80

+KTCPCFG: 1

OK
AT+KTCPCNX=1
AT+KTCPCNX=1

OK

+KCNX_IND: 1,1,0

+KTCP_NOTIF: 1,5
AT+CSQ
AT+CSQ

+CSQ: 31,0

OK

2

Hi @aidanvander

I can start a TCP connection successfully on the HL7800 firmware HL7800.4.5.4, NBIOT.
Please provide some information about your module and SIM card using the below commands:
AT+CGDCONT?
AT+CGACT?
AT+KSLEEP?
AT+CPSMS?
AT+CEDRXS?
AT+CEREG?
AT+COPS?
AT+CGPADDR
AT+CGPADDR

I have attached the log file for your reference. Log_HL7800.txt (526 Bytes)

3

Hi @Donald

Thank you for the reply!

Here is the output of the commands you provided. Please let me know if you notice that something is incorrect.

at+cgdcont?
at+cgdcont?

+CGDCONT: 1,“IP”,“lte.vodacom.za”,0,0,0,0,0,0,

OK
AT+CGACT?
AT+CGACT?

+CGACT: 1,1
+CGACT: 2,0
+CGACT: 3,0
+CGACT: 4,0
+CGACT: 5,0
+CGACT: 6,0
+CGACT: 7,0
+CGACT: 8,0
+CGACT: 9,0
+CGACT: 10,0
+CGACT: 11,0
+CGACT: 12,0
+CGACT: 13,0
+CGACT: 14,0
+CGACT: 15,0

OK
AT+KSLEEP?
AT+KSLEEP?

+KSLEEP: 2

OK
AT+CPSMS?
AT+CPSMS?

+CPSMS: 0,“11100000”,“11100000”,“00101100”,“00001010”

OK
AT+CEDRXS?
AT+CEDRXS?

OK
AT+CEREG?
AT+CEREG?

+CEREG: 0,1

OK
AT+COPS?
AT+COPS?

+COPS: 0,0,“VodaCom-SA”,9

OK
AT+CGPADDR
AT+CGPADDR

+CGPADDR: 1,“10.79.195.70”

OK

4

Hi @aidanvander

The output of these commands is correct.
Can you start a TCP connection on HL7800 CAT-M1 (AT+KSRAT=0)?

Please restart the module and try again.

5

There is no CAT-M1 coverage in South Africa:

AT+KSRAT?
AT+KSRAT?

+KSRAT: 0

OK
AT+CSQ
AT+CSQ

+CSQ: 99,99

OK
AT+COPS?
AT+COPS?

+COPS: 0

OK

Here is NB IOT, the signal strength doesn’t look great though?

AT+KSRAT?
AT+KSRAT?

+KSRAT: 1

OK
AT+CSQ
AT+CSQ

+CSQ: 31,0

OK
AT+COPS?
AT+COPS?

+COPS: 0,0,“VodaCom-SA”,9

OK

6

Hi aidanvander,

Signal strength is okay. You can attach the antenna to the module and move the antenna, module away from noisy equipment for better signal strength.

> **+CSQ: <rssi>,<ber>**
> **<rssi>** Received signal strength indication
> 0 -113 dBm or less
> 1 – 30 -111 to -53 dBm
> 31 -51 dBm or greater
> 99 Not known or not detectable
> **<ber>** Integer type; channel bit error rate (in percent)
> 0 – 7 As RXQUAL values in the table in 3GPP TS 45.008 [20] subclause 8.2.4
> 99 Not known or not detectable

Are you still having this issue after restarting the module?

7

@aidanvander

I would say that generically you are doing everything right to make a connection successfully.

So with a lot of the Voda NB1 implementations globally they do not necessarily give you straight internet access which allows you to connect to say Google on port 80. The URL/IP address you are trying connect to may well need to be on a list that they hold in their firewall. You might be able to stick the SIM into an LTE cat 1 device and make the connection but NB1 traffic is probably routed differently with in the network.

Regards

Matt

8

@Donald Yes, still he same issues.

@mlw That is interesting, I was not aware of this. I will investigate further, thanks.