TMA (Time Adjustment)

The AT@TMA command is used to help the terminal calibrate the local time. The terminal always automatically performs time synchronization.

The terminal can automatically obtain UTC time from the base station, NTP server or GNSS, and then uses the ‘Time Zone’ and ‘Daylight Saving’ parameters to calculate the local time.

Note: In the case that the terminal cannot obtain the real UTC time through GNSS or network, the user can issue subcommand 98 of the AT@RTO command to calibrate the UTC time. Once the terminal obtains the real UTC time through GNSS or network, it will automatically calibrate the UTC time.

Example:
AT@TMA=gl601###,,+32,0,,time.windows.com,123,012F$
+ACK:TMA,123456789012345,C031,10,0,,012F,20210407101530,1234$
AT@TMA?gl601###,,0C37$
+QRY:TMA,123456789012345,C031,10,0,1,1,,+32,0,,time.windows.com,123,0C37,20210407101530,1234$

Parts

Fields

Length (Byte)

Range/Format

Default

Head

Header

3

AT@

AT@

Command Word

3

TMA

TMA

Leading Symbol

1

=

=

Password

8-16

gl601###

Body

Reserved

0

Time Zone

<=3

-48 to +48 (*15 minutes)

0

Daylight Saving

1

0-1

0

Reserved

0

NTP Server IP or Domain Name

<=64

time.windows.com

NTP Server Port

<=5

1 - 65535

123

Tail

Sequence Number

4

0000-FFFF (‘0’-‘9’, ‘A’-‘F’)

Tail

1

$

$

  • Time Zone

    Time zone, a signed integer, indicates the difference, expressed in quarters of an hour, between the local time (excluding daylight saving time) and UTC.

    For example, the value of this field is “+32”, which means UTC+08:00.
    For example, the value of this field is “-8”, which means UTC-02:00.
    For example, the value of this field is “-10”, which means UTC-02:30.

    Note

    This parameter follows the following conventions:

    1. If the value is zero, then no plus or minus sign (+/-) is displayed before the value.

    2. If the value is below zero, then the minus sign (-) is displayed before the value.

    3. If the value is above zero, then the plus sign (+) is displayed before the value.

  • Daylight Saving

    • 0 - Disable. There is no need to add 1 hour to local time.

    • 1 - Enable. The local time needs to be added by 1 hour.

  • NTP Server IP or Domain Name

    The IP or domain name of the NTP server.

    The terminal will only try to access the NTP server when it cannot obtain the UTC time via the GNSS chip and the base station, and access it at most once within 24 hours.

  • NTP Server Port

    The port of the NTP server.