Huawei MU609 - Exception Handling; Module Reset; Module Going to Dump Status

HUAWEI MU609 HSPA LGA Module
Application Guide
Appendix
Issue 02 (2013-09-18)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
144
19.3 Exception Handling
In the industrial product design, in order to ensure reliable operation of the device for
a long time, the host need take into account fault-tolerant design. This is because
that the operation of the terminal environment is very complex and not easy to design
the system architecture for complete simulation. Since the environment maybe
change, and the various hardware components within the device are not always
guaranteed to work at the expected condition, even if the module is able to maintain
the electrical specifications claimed to work, but the external signal may also lead to
abnormal changes in the module beyond the normal working condition. For example,
the power supply voltage drop may cause the module reboots, so we recommend in
the system design customers should consider the types of abnormal events, and add
a corresponding recovery process, so that the module can be restored after a brief
interruption to the normal communication.
19.3.1 Module Reset

Exception Description
In some extreme condition (for example, the power voltage is not stable), the module may
be reset.

How to Detect the Exception by the Host
The module will report "^SYSSTART" to the host.

Host Resume Steps
After the module reset, the host need reconfigure the configuration, and reconnect
the data service, if the module was connected to network before resetting. If the
module is connected to network by embedded protocol IP stack or external protocol
stack, the host need reconnect too.

Host Resume Example
For the data service reconnected by external protocol stack, please take the following
two steps.
Step 1 Input AT+CGDCONT=1,"IP","1234"
Step 2 Input ATD*99#
For detail, please refer to Chapter 4 External Protocol Stack Application Scenarios.
19.3.2 Module Going to Dump Status

Exception Description
In some extreme condition, the module may go to dump status to protect itself. In this
status, it cannot response to any ATcommand, and its USB port status is not the same as
normal status.

How to Detect the Exception by the Host
Any AT command input will have no response, and the module only has two USB ports.

Host Resume Steps