Specifications

Smart Machine Smart Decision
SIM900_AT Commands Manual_V1.07 58 2012.12.10
OK
Parameter
<type> Current address type setting.
Response
OK
If <type> is not in the parameter range:
ERROR
Write Command
AT+CSTA=<type
>
Parameter
<type> Type of address octet in integer format;
129 Unknown type
161 National number type
145 International number type
177 Network specific number
Reference
GSM 07.07 [13]
Note
The ATD Command overrides this setting when a number is dialed.
3.2.14 AT+CHLD Call Hold and Multiparty
AT+CHLD Call Hold and Multiparty
Response
+CHLD: (list of supported <n>s)
OK
Test Command
AT+CHLD=?
Parameter
See Write Command
Response
TA controls the supplementary services Call Hold, Multiparty and Explicit
Call Transfer. Calls can be put on hold, recovered, released, added to
conversation, and transferred.
Note These supplementary services are only applicable to tele service 11
(Speech: Telephony).
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CHLD=<n>
Parameter
<n> 0 Releases all held calls or sets User Determined User Busy