Why does the CCLK instruction sometimes return different data formats?

RE: Why does the CCLK instruction sometimes return different data formats?

Raoul — Tue, 18 Apr 2023 19:33:07 GMT

[quote user="duxinglang"]I am concerned if there is a flaw in the modem, such as when it was just registered on the network and was still calculating CCLK data, my program sent instructions to it, causing it to not have time to parse the complete time zone information. Is this possible?[/quote]

I understand your concern, but I don't know whether this is possible or not. I've asked my colleagues, and so far no one has any theories about this. Would you be able to produce a modem trace?

Best regards,

Raoul

RE: Why does the CCLK instruction sometimes return different data formats?

duxinglang — Fri, 14 Apr 2023 03:31:29 GMT

I have used China Mobile's network, and in most cases, the commands it replies to are in a time zone format. However, there have been several replies without a time zone format in certain areas where the signal is not good or from no signal to signal. Sometimes, even when it is the same base station, two formats of replies are returned in a short period of time. I do not believe that the operator's base station will randomly reply to commands in different formats, I am concerned if there is a flaw in the modem, such as when it was just registered on the network and was still calculating CCLK data, my program sent instructions to it, causing it to not have time to parse the complete time zone information. Is this possible?

RE: Why does the CCLK instruction sometimes return different data formats?

Raoul — Tue, 04 Apr 2023 19:06:20 GMT

Hi,

As you seem to know, the segment after the "+" is indeed timezone information, interpreted as follows:

Time zone indicates the difference, expressed in quarters of an hour, between the local time and GMT (value range from −48 to +48) (infocenter)

But regarding the two responses, it seems that it's up to the cellular provider to define their response. Which provider are you using? This reply by another DevZone user mentions the two possible formats, although I'm a bit puzzled by them both appearing. Do you mean you randomly get one of the two formats? Or do you get both returned at the same time?

Note that I'm not a cellular expert, you might have to wait until after the Easter Holiday for them to return to the office if we need more expertise.

Best regards,

Raoul