QUECTEL UC20 Time Synchronization

IoT Modules GSM Module
1

Hello, I’m using TD210: IoT Cellular Modem and I want obtain the RTC using AT commands.

If I use the next command, the return response is wrong.
AT+CCLK?
+CCLK: “80/01/06,00:00:00-24”

But if I use first the command:
AT+CTZU=1
AT+CCLK?
+CCLK: “24/06/05,13:20:00-24”
The date and time are updated, but the update corresponds to GMT.

I saw in other responses that using the command as follows AT+CTZU=3 allows you to enable automatic time zone update via NITZ and update LOCAL time to RTC, but the uc20 Quectel series doesn’t let you set the command AT+CTZU with a 3.

How can I resolve it?

2

That’s correct behaviour. You need to apply the local offset, the trailing “-24” in your case.

That’s -(24/4) hours. So 6 hours behind UTC/GMT. The units are ¼ hours, and the “-” implies behind UTC.

I get:

AT+CCLK?
+CCLK: "24/06/05,21:14:13+40"

which correctly implies I’m 10 hours ahead.

3

Thank you for the answer.
So there is no way to perform the conversion in AT commands?

4

Not that I’ve found. Values of <onoff> in AT+CTZU=<onoff> other than 0 or 1 do not comply with 3GPP 27.007.