sim 900 time update psuttz problem

I am using Sim 900 module for my project at startup i am giving following at commands.

AT
ATE0
AT*PSUTTZ=1
AT+CLTS=1
AT+CIURC=1

Then i when i give AT+CFUN=1,1 then in some sim cards it is giving PSUTTZ at the modem restart but in some sim cards it is giving the string. In some sims i have observed that some times psuttz is coming sometime and it is not observed in some restart.

Eg. I have used two vodafone sim cards in one sim card it is giving psuttz at the startup and in second sim card it is giving psuttz some time and some time it is not giving.

I need psuttz because it is the way i can confirm that the at+cclk will be give the updated network time. I also know normally all service providers provide network time facility, then is there any way that the network time can be forced to get updated from the network.

For a start AT*PSUTTZ=1 does nothing, look at the AT commands manual. You are already enabling this notification with AT+CLTS=1.

As to the missing *PSUTTZ: 2013, 7, 24, 3, 59, 13, "+40", 1 at startup, your provider is simply not sending the NITZ data when the modem connects to the local tower. What I have found is that a given provider wil ALWAYS either give the notification or not, whatever tower I happen to connect to. Are you saying that sometimes with the modem in the same location (and presumably connecting to the same tower) you sometimes do not see the *PSUTTZ: ... notification?

As to forcing time update, I don't think that you can do that.

Keep me updated as I am doing a very similar thing. We choose SIM cards very carefully to work reliably in different locations, and Vodafone simply never give the update at all (I am in Australia). Try asking the provider about NITZ and watch the blank look spread across their face.

I have since moved over to using the Quectel M95 module since I met the CEO of Quectel and gained a load of insights into using GPRS modems (and the price & performance of Quectel modems are good too!). The M95 has an inbuilt command to use NTP to sync the internal RTC to a network time server of your choice, but I found the default server in China works just as well as anything.

AT+QNTP /* Perform the sync. */
OK

+QNTP: 0 /* URC giving result, in this case, success! */

How easy is that? Go Quectel!