AT commnads of HSDPA module

[junhorng]

I used a micro-processor to send AT command to a HSDPA module via
UART. However, when the " ATD *99# " is sent and the " CONNECT " is
therefore received, the micro-processor can not send commands to the
HSDPA module any more. Does anyone know to how to manipulate the
module in this step.

Thanks

[John Henderson]

Post by junhorng
I used a micro-processor to send AT command to a HSDPA module via
UART. However, when the " ATD *99# " is sent and the " CONNECT " is
therefore received, the micro-processor can not send commands to the
HSDPA module any more. Does anyone know to how to manipulate the
module in this step.

The default modem sequence to escape to command mode is "+++"
(three plus characters) in quick succession, but with a
pronounced pause either side. The pauses either side are known
as the "guard time", and this prevents accidental switching to
"AT" command mode whenever "+++" is transmitted as a legitimate
sequence within a data stream (as when I post this reply
using my modem, for example).

The character used in the escape sequence is probably
configurable, but defaults to "+".

To switch back to data transfer mode from command mode, the "AT"
command is:

ATO

(that's the letter "O").

John

[junhorng]

Post by John Henderson

Post by junhorng
I used a micro-processor to send AT command to a HSDPA module via
UART. However, when the " ATD *99# " is sent and the " CONNECT " is
therefore received, the micro-processor can not send  commands to the
HSDPA module any more. Does anyone know to how to manipulate the
module in this step.

The default modem sequence to escape to command mode is "+++"
(three plus characters) in quick succession, but with a
pronounced pause either side.  The pauses either side are known
as the "guard time", and this prevents accidental switching to
"AT" command mode whenever "+++" is transmitted as a legitimate
sequence within a data stream (as when I post this reply
using my modem, for example).
The character used in the escape sequence is probably
configurable, but defaults to "+".
To switch back to data transfer mode from command mode, the "AT"
        ATO
(that's the letter "O").
John

Thanks for your reply.

I have tried "+++" as your suggestion, the HyperTerminal is still
blocked. In this situation, unless I disconnected the HyperTerminal
and connect it again, I can not type characters any more. I am very
appreciated for your further suggestion.

[John Henderson]

Post by junhorng
I have tried "+++" as your suggestion, the HyperTerminal is still
blocked. In this situation, unless I disconnected the HyperTerminal
and connect it again, I can not type characters any more. I am very
appreciated for your further suggestion.

I'm not sure whether Hyperterminal buffers output until a
<carriage return> is entered. If it does, this would mean you
can't use the escape-to-command-mode sequence from Hyperterminal,
because buffering would prevent your implementing guard time
correctly.

John