Aborting ATD*99***1#

IoT Modules Legacy HL Series
1

Is there a safe way to abort ‘ATD99**1#’ ?

Image if I want the dial command to finish in let’s say maximum one minute, can I after that time abort the dial safely (+++ and/or ATH seem to lock the module forever in this situation)? Or do I need to wait until the command is finished? And what is the maximum execution time of ATD?

The module I’m currently using is HL7692

2

Hi Roel0,

To abort the PPP connection, you need to send +++ and then ATH.
ATD*99#
CONNECT
~}#?}!}!} }4}"}&} } } } }%}&f燾6}’}"}(}"刕~~}
…
//Send +++
OK
ATH
OK

3

Yes but I’m talking about the corner case where you want to abort ATD before it has responded with CONENCT/…

4

We cannot abort ATD*99# before CONNECT responed.

5

Thanks for the info, what is the maximum amount of time before the HL module will repsond to the ATD command?

6

In my test(10 times), “CONNECT” occurs 1-20 ms after ATd*99#.

7

In some corner cases, ATD seems to never respond:
09:20:54 Send: ‘ATD99*1#’
09:20:54 Recv: 'ATD99***1#’
09:21:07 Recv: ‘+CREG: 0’

The only solution I currently have, is reboot the complete system…

How do I trigger this behavior? On the reception of a +CREG: 1 unsolicited, I’ll react by opening a PPP connection. On reception of +CREG: different from 1, I’ll abort the PPP connection.
By removing and re-attaching the antenna, I 'm testing this behavior, but sometimes I see ATD never response and seems to lock the HL module

8

Hi Roel0,

Please make sure +CGREG:1 before starting the PPP connection.
And I suggest contacting your Sierra Wireless sales/technical support person for more support.