Embedded Files
This section is intended to provide you a quick guide on how to setup the connection of your R4/R5 modules using AT commands so that you can easily test the service. For a complete documentation, refer to document SARA-R4 / SARA-R5 Internet applications development guide
Network setting verification
The following example reports the AT commands necessary to reach the activation of a PDP context at first then a data socket by starting from the power-up of the module and the control of the pre-existing settings.
AT+CFUN=0 - Turn OFF the radio functionality to set the network profile
AT+UMNOPROF=100 - Set the MNO profile for usage in Europe. For other countries look at UMNOPROF command in AT Command manuale
AT+CFUN=16 - Reboot the modules to make the new settings effective
AT+UMNOPROF? - Verify that the new profile has been set
AT+CFUN=0 - Turn OFF the radio
AT+CGDCONT=1,"IPV4V6" , "apn_name" - Define the PDP context 1 with PDP type "IPV4V6" and APN "apn_name" of the MNO
Network registration check
LTE radio access technology
Verify that the module is registered on the LTE network
AT+CFUN=1 - Turn ON the radio
AT+COPS? - verify if the module is currently registered to the network
+COPS: 0,0,"Your MNO",7
where
0 is the default value for mode, and format (for more information you are invited to look at AT Command manual)
7 represent the act that indicates the radio access technology (LTE=7)
AT+CEREG? - Valid responses are
+CEREG: 0,5 - registered to network in roaming (5)
+CEREG: 0,1 - registered to home network (1)
AT+CGATT? - where the valid response is
+CGATT: 1 - attached to the network
AT+CGDCONT? - Get the IP address assigned by the network to the module
+CGDCONT: 1,"IP","MNO_APN_url","10.66.197.221",0,0,0,2,0,0,0,0,0,0,0
where 10.66.197.221 is the IP Address assigned to your device by the MNO. For a complete list of the parameters you are invited to look at the AT Command manual
GPRS/eGPRS radio access technology
Verify that the module is registered on the 2G network
AT+CFUN=1 - Turn ON the radio
AT+COPS? - verify if the module is currently registered to the network
AT+CGACT=1,1 - Activate PDP context 1
AT+CGDCONT? - Get the IP address assigned by the network
Profile activation
SARA-R5 modules
AT+UPSD=0,0,0 - Set the PDP type to IPv4 referring to the output of the +CGDCONT read command
AT+UPSD=0,100,1 - Map the profile on CID=1
AT+UPSDA=0,3 - Activate the PSD profile #0: the IPV4 address is already assigned to the network
+UUPSDA: 0,"10.66.197.221"
SARA-R4 modules
AT+UPSD=0,0,0 - Set the PDP type to IPv4 referring to the output of the +CGDCONT read command
AT+UPSD=0,100,1 - Map the profile on CID=1
After these sequence you are ready to use the CellLocate service issuing the AT+ULOC command to get the location, as described in the getting started guide.
Check radio signal
It might be also useful to check the radio signal with
AT+CSQ
The module response is in the format
+CSQ: <signal_power>,<qual>
+CSQ: 24,5
The response provides the RSSI (Received Signal Strength Indication) and the quality indicator (represented by RSRQ). The value mapping for both parameters is provided in the two tables below
DNS verification
The CellLocate client in the cellular module needs to resolve the url endpoint provided in the UGSRV command regardless if you are using the Device to Service endpoints (cell-live1.services.u-blox.com, cell-live2.services.u-blox.com ) or the Service to Service mode with your application server endpoint
In the case you are not able to get a position from CellLocate service, you might verify if you are getting the DNS IP address from the service provider. For this purpose you can use the following command to verify the PDP context providing in input the ID of the connection (1 in the following example)
AT+CGCONTRDP=1
+CGCONTRDP: 1,5,"TSIOT","10.66.199.116","","212.9.0.135","212.9.0.136"
The reply (+CGCONTRDP) provides back the following relevant information:
the APN: TSIOT in the example
the IP address assigned to your device by the network operator: 10.66.199.116 in the example
Primary and secondary DNS server IP addresses: 212.9.0.135 and 212.9.0.136 in the example
If you do not get back this information , it means that the connection is not properly established and it's not possible to use CellLocate service. If you are getting back the only the device IP address but not the DNS IPs, it means that the network operator is not providing you such information. In this case:
In SARA-R5 you can set your own DNS IPs by using +UPSD AT command. You are invited to look at the latest version of AT command manual in the u-blox website
In SARA-R422, the feature for DNS IPs manual setting will be available in a future firmware using the same command as for R5. We invite you to check the corresponding AT command manual or contact the support
You can set any public DNS IP, just choosing your preferred ones.
To verify if DNS IPs are properly set you can use the following AT commands:
To verify that the DNS servers are reachable set the IP address of primary or secondary DNS (obtained through AT+CGCONTRDP command as explained above. DNS IPs are usually provided by your network operator. In the below example Google DNS is used and a valid reply is shown
AT+UPING="8.8.8.8"
OK
+UUPING: 1,32,"dns.google","8.8.8.8",114,85
+UUPING: 2,32,"dns.google","8.8.8.8",114,77
+UUPING: 3,32,"dns.google","8.8.8.8",114,77
+UUPING: 4,32,"dns.google","8.8.8.8",114,74
The response uses the following format
+UUPING: <retry_num>,<p_size>,<remote_hostname>,<remote_ip>,<ttl>,<rtt>
Note: for security reason the u-blox CellLocate service endpoints (cell-live1.services.u-blox.com, cell-live2.services.u-blox.com)do not reply to ping command.
To verify that an url can be properly translated/resolved in an IP address by the DNS server
AT+UDNSRN=0,"www.u-blox.com"
+UDNSRN: "34.159.25.198"
OK
or
AT+UDNSRN=0,"cell-live1.services.u-blox.com"
+UDNSRN: "34.240.192.217"
OK
Private APN and Firewall
In case that all your devices are using a private APN and a there is a firewall to restrict the connections, be aware that:
UDP Port 53 shall be opened to allow DNS resolution
TCP port 80 shall be opened to allow the CellLocate request
In this section
Still need help?
If you need more help or have any questions, please send an email to services-support@u-blox.com.
SARA-R5 connection troubleshooting guide
This section explains how to identify and solve some typical issues related to network connection.
First module connection
When the module connects to the network for the first time (or after a refurbish procedure), it can take several minutes to connect (between 5-10 minutes) depending upon the signals and quality of the network in that area. This is due to the fact that the module comes with a pre-set MNO profile value, either global or Europe. Hence, the module starts scanning for all the band masks that fall under the global/Europe MNO.
To speed up the connection, it is recommended to set the profile to the MNO of the region the module is being used in:
AT+UMNOPROF = <MNO>
To further speed up the connection, it is recommended to provide the specific band mask using
AT+UBANDMASK = <RAT>, <bitmask1>[,<bitmask2>]
A reboot shall be applied (AT+CFUN=16) to apply the above changes.
After the connection is established, the network settings are saved in the module for the successive connections.
Band MASK
It is the range of radio frequencies supported in the area the module is being used in. A band mask can be obtained by searching for the bands used by the network operators in a given area. If the device is already connected to the network, you can use this command to see the used bands
AT+UCGED?
Before querying the bands, you need to set the module using the command below:
AT+UCGED = 2
Subsequent connections
After the first connection, the subsequent connections take considerably less time, usually seconds, to connect to the network. The time is reduced because the module first looks to the saved settings from the previous connection and use those first to try to connect to the network.
Behavior after firmware update
During the firmware update, the module loses the saved settings from the previous connection. Thus, after every firmware update, the module will take longer time to connect to the network like it took for the first connection establishment.
To speed up the connection, it is recommended to note down the UBAND mask and MNO before the next firmware update and configure the module accordingly before trying for a fresh connection after the firmware update.
Poor connectivity condition
If the SARA-R5 module frequently loose the network connection, start with the basic debugging steps given as following:
Make sure that the SIM card is not physically damaged.
Check if the SIM card is properly seated in the device or not.
Verify the module is not in power saving mode using
AT+UPSV?
For power saving, 0 means the mode is disabled and 1 refers to mode enabled.
If after basic debugging, SARA-R5 module continues to lose network connection frequently, this may be be caused by a poor network connectivity area or weak signal strength. You can verify it by using the
AT+CESQ=?
Move the device to a good network visible area. Being placed in poor network connectivity area, the module takes longer time to connect to the network and may often lose network connection based on signal quality.
Roaming behavior
When the SARA-R5 module is in roaming mode, the module can take longer than usual to connect to the network. As best practice:
Set the module’s MNO profile to global (90).
Provide UBAND mask for a range of radio frequencies (RATs) supported in the area.
Initial first scan may take 5 minutes for full scan. The command given below performs a full scan for all the available networks.
AT+COPS=?
Reboot the SARA-R5 module to make the setting effective and for quicker successive connection using this command:
AT+CFUN=16
Firmware update of SARA-R5 on XPLR-IOT-1 Kit
SARA-R5 on XPLR-IOT-1 kit uses two UARTs to carry out its tasks. When the module on the kit is subjected to firmware update, one of the two UARTs is disabled. To bring it back to work, connect the device to m-center and use the following AT command:
AT+USIO=2
NOTE: For further connectivity details of SARA R5 with XPLR-IOT-1 kit, refer to section 5.3 of XPLR-IOT-1 kit user guide.
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