HC25 AT Command Set - Portech.com.tw

HC25 AT Command Set
1.8 Unsolicited Result Code Presentation
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1.8 Unsolicited Result Code Presentation
URC stands for Unsolicited Result Code and is a report message issued by the ME without being requested by
the TE, i.e. a URC is issued automatically when a certain event occurs. Hence, a URC is not issued as part of
the response related to an executed AT command.
Typical events leading to URCs are incoming calls ("RING"), waiting calls, received short messages, changes in
temperature, network registration etc. For most of these messages, the ME needs to be configured whether or
not to send a URC. Descriptions of these URCs are provided with the associated AT command. Only the URCs
related to automatic undervoltage and overvoltage shutdown are not user definable. These URCs are described
in Section 1.8.1, Common URCs. A summary of all URCs can be found in Section 19.5, Summary of Unsolicited
Result Codes (URC).
As specified in Section 1.4, HC25 AT Command Interpreter the modem interface is dedicated for data transmission
(HSDPA, GPRS, CSD). The application interface is designed primarily for control functions. This implies that
the majority of URCs are normally issued on the application interface, no matter which of the AT interfaces was
used to send the AT command for activating their presentation. Only URCs relevant for data calls (RING, NO
CARRIER) are issued on the modem interface to ensure compatability with existing modem applications.
If the interface is blocked by a running AT command, the URCs are buffered internally and issued when the interface
becomes idle again. There is no inband signaling if a URC is buffered.
Enabled by default when the ME is powered up, the above URC management scheme is the recommended
approach for a typical HC25 application. Yet, as an alternative to this approach, the configuration command
AT^SCFG provides the option to determine the interface used for issuing the URCs. Refer to the parameter
for details. IMPORTANT: When using the modem interface for URC output, keep in mind that if the interface
is blocked by an active data connection you are required to suspend the connection at regular intervals to check
for pending URCs because inband signaling is not supported.
HC25_ATC_V01.200 Page 23 of 290 7/25/07
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