Sara AFF R410M 02B-01 fails to register to nbiot network

Hi,
formerly I tested a SARA R410M 02b-00 to connect to nb-iot netvork by vodafone (IT), use UDP sockets and everything worked fine.

Now I got a batch of new SARA R410 02b-01 and I am not able to register on the network; the last command that fails in the initialization sequence is :

AT+COPS=1,2,“22210”
<< +CME ERROR: no network service

I checked if it is the case of a firmware upgrade but it’s not worth: i have already the last version L0.0.00.00.05.12,A.02.19

Following is the full working sequence of AT commands my application sends to the module.
(with the new module the sequence is locked at +CME ERROR)

What am I doing wrong ?

kind regards

Alessandro


AT
<< OK

AT+CMEE=2
<< OK

AT+CFUN=15
<< OK

AT+CPIN?
<< +CPIN: READY
<< OK

ATE0
<< OK

AT+UMNOPROF?
<< +UMNOPROF: 19
<< OK

AT+UBANDMASK=1,524288
<< OK

AT+URAT?
<< +URAT: 8
<< OK

AT+CEREG=3
<< OK

AT+CGDCONT=1,“IP”,“nb.it.vodafone.iot”
<< OK

AT+CFUN=1
<< OK

AT+COPS=1,2,“22210”
<< OK // in case of R410M 02B-01 << +CME ERROR: no network service

<< +CEREG: 5,“69D9”,“98F56F”,9

AT+CGDCONT?
<< +CGDCONT: 1,“IP”,“nb.it.vodafone.iot”,[a valid ip address],0,0,0,0
<< OK

AT+CSQ
<< +CSQ: 1,99
<< OK

AT+CPIN?
<< +CPIN: READY
<< OK

AT+CCID
<< +CCID: [my sim CCID]
<< OK

AT+USOCR=17,16666
<< +USOCR: 0
<< OK

AT+UDCONF=1,1
<< OK

AT+USOST=0,[my host IP],[my host port],82,"[my 82 bytes of data]"
<< +USOST: 0,82
<< OK

Hi @alelig,

I assume you have two boards.
One with the older firmware and the other with the latest firmware.
The one with the older firmware works, so it shouldn’t be a network coverage issue.

A CSQ of 1 is very poor, do you have another antenna you can attach to the new board to see if it will perform better? Or swap the antenna’s, be careful with the u.fl connector it’s very fragile.

Best regards,
Jan

Hi Jan,
yes, I have two boards, respectively with older and latest firmware.
yes, the CSQ was poor and now with a proper location of the apparel I get a CSQ from 13 to 18, but it alone didn’t solve the lock during the execution of AT+COPS=1,2,“22210” command.

Anyway, with some other adjustments, now my program is working. Please tell me if I am somehow wrong I what I understood:

  1. ublox documentation states that the module goes in sleep mode after 6 sec of inactivity; but it does it only if the parameter UPSV is > 0 and the factory default is UPSV=0.
  2. I realized that my module goes in sleep mode after nearly 12 sec in spite of a query AT+UPSV? returns 0.
  3. depending on location, signal strenght, etc, the commad AT+COPS=1,2,“22210” gains the operator network between 15 and 20 sec.
    Is it possible that waiting for the network operator the module goes in sleep mode ? (sleep timeout < time to get network) ?

To let the things work I forced the following commands after module power-up:
AT+UPSV=0 and AT+CPSMS=0

What do you think about it ?

Kind regards
Alessandro

Just a few notes:

Before setting +UMNOPROF, +UBANDMASK & +URAT you must first put the modem offline +CFUN=0. After setting any of those commands you must reboot the module for the setting to take effect +CFUN=15. Note that after a reboot the module takes 5-10s before it is responsive again. As doing three reboots every time is in efficient, you may want to check the current setting and only change (and reboot) when necessary.

Using +UPSV the UART becomes unresponsive after 6s of inactivity, this is because the module disables the UART after that timeout to save power. Sending further data over the UART will reactivate it, however, this usually means the first command (which wakes the UART) is lost. As you can imagine this can cause issues with AT command sequences.

Unless you specifically want to use PSM you should always make sure it is disabled +CPSMS=0. When PSM is enabled, upon expiry of T3324 the timer, the module will enter a very low power state, and will be unresponsive over the UART. In order to wake the device out of PSM you have to toggle the IO pins in a similar way as when you power on the module.