Gemalto/Cinterion PLS62T modem LTE not working unless 3G is also available

Our PLS62-T modems were sold using this tag line: “Multi-Band LTE Cat 1 with 2G / 3G Fallback for Seamless Global Connectivity”.

However, we are having issues when our modem is only registered LTE and 3G is NOT Available.

Here is our modem configuration and a simple test showing the issue we are having. Is there some other configuration setting(s) that will allow us to operate with only LTE?

Thank you,
Chris

========================
AT&V

ACTIVE PROFILE:

E0 Q0 V1 &C1 &D2 &S0 \Q3
S0:000 S3:013 S4:010 S5:008 S6:000 S7:060 S8:000 S10:002
+CMGF: 1
+CSDH: 0
+CNMI: 0,0,0,0,1
+ICF: 3
+IPR: 115200
+CMEE: 2
+CSMS: 0,1,1,1
+CREG: 0,3 <== not registered 3G
+CEREG: 0,1 <== Registered LTE
+COPS: 0,0,“T-Mobile”,7
+CGSMS: 1
OK

AT+CGATT?
+CGATT: 1
OK

AT^SXRAT?
^SXRAT: 5,3
OK

Manual SMS send showing results

AT+CMGF=1
OK

AT+CMGS=“2936”
This is a test

+CMS ERROR: MM No Service (out of coverage)

Hi Chris.

I am going to do a little research on this and will get back to you as soon as possible.

Thanks.
Curtis Johnson

Thank you. I really appreciate your help!
Chris

I’m sorry for the delay Chris. Here are some additional questions:

  1. How often is the issue occurring?
  2. Was it checked on other modules?
  3. What does simplest steps for reproduction look like?
  4. Is there a possibility to provide AT log (preferably with timestamps) Additionally, I need: Full firmware version: revision and a-revision (ATI1 response).

Curtis

Curtis,

Here is the configuration we are using and a simple command sequence showing the error I get when there is no 3G connection. If the modem has a registered 3G connection the simple test works.

We are using Twilio Programable Wireless SIMs.

From what I see on Twilio, it appears that my SMS message is sent via LTE when the modem has both an LTE and 3G connection.

Modem configuration Follows:

Hi Chris.

It seems the modem configuration wasn’t included. Can you attached that please?

Thanks.
Curtis

========================================================================
ATI1 <== This is the firmware that is loaded on each of our modems
Cinterion
PLS62-W
REVISION 02.010
A-REVISION 01.000.11

OK

========================================================================
Below is a snippet of code showing EXACLTY how I setup each modem.
Each command is executed “in order” and returns an “OK” before a modem is deployed

        string[] modem_config_cmds = {
                "ATI1",                                                // Display mode & Firmware
                "AT+COPS=2",                                   // Manually unregister from the Network .. Just in case it is already registered
                "AT&F",                                              // Restore the factory Default settings
                "AT&V",                                              // Show the current configuration
                "AT^SCFG=\"Userware/Autostart\",\"\",\"0\"",    // Turn off any factory installed program(s)   Specifically EZeye   AND sometimes the remote access
                "AT^SJAM=5",                                   // List running modem applications .. if found, we need to disable them
                "ATE0",                                              // Turn off echoing of commands entered
                "AT+CMGF=0",                                  // Turn on PDU mode for SMS messages (versus using TEXT mode)
                "AT+CNMI=0,0,0,0,1",                       // SMS UCR event message configuration
                "AT+IPR=115200",                             // Baud rate for serial interface
                "AT+CREG=0",                                  // Disable registration messages .. the PLC will poll for them
                "AT+COPS=4,0,\"T-Mobile\"",            // Try T-Mobile as Network/Operator before looking at other operators 
                "AT^SXRAT=5,3",                               // Use LTE and Fall back to GSM if LTE not available
                "AT+CMEE=2",                                   // Error message Format .. 2=Verbose strings
                "AT+CSMS=0",                                   // Select Message Service .. 0 seems to be the default for USA
                "AT+CGSMS=1",                                 // Select service for short messages 1 seems to be the default for USA
                "AT^SLED=2",                                     // Make the LED light blink when registered
                "AT^SCFG=\"GPRS/AutoAttach\",\"enabled\"",     // Might need this in the future
                "AT^SCFG=\"Tcp/WithURCs\",\"off\"",                   // Don't use IP
                "AT^SCFG=\"Userware/Watchdog\",\"1\"",            // Leave watchdog on to auto reboot modem if necessary
                "AT&W",                                                               // Persist this config .. so we can reboot it :)
                "AT+CFUN=1,1"                                                  // Restart the modem to full functionality using the new configuration
        };

========================================================================
Here are commands showing a configured modem followed by a simple SMS send command showing the error we get when a 3G connection is not available:

AT&V

ACTIVE PROFILE:

E0 Q0 V1 &C1 &D2 &S0 \Q3
S0:000 S3:013 S4:010 S5:008 S6:000 S7:060 S8:000 S10:002
+CMGF: 1
+CSDH: 0
+CNMI: 0,0,0,0,1
+ICF: 3
+IPR: 115200
+CMEE: 2
+CSMS: 0,1,1,1
+CREG: 0,3 <== not registered 3G
+CEREG: 0,1 <== Registered LTE
+COPS: 0,0,“T-Mobile”,7
+CGSMS: 1
OK

AT+CGATT?
+CGATT: 1
OK

AT^SXRAT?
^SXRAT: 5,3
OK

*** This is a simple manual SMS send showing the results I am receiving ***

AT+CMGF=1
OK

AT+CMGS=“2936”
This is a test

+CMS ERROR: MM No Service (out of coverage)

Modem Info Sent to Support 2022-03-02.txt (4.2 KB)

Please find the requested information attached
Chris

Curtis … do you think that you will be able to help me?