MC55 AT Command Set
9.8 AT+CHLD s
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MC55_ATC_V01.05 Page 230 of 469 2/10/04
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9.8 AT+CHLD Call Hold and Multiparty
Syntax
Command Description
TA controls the Supplementary Services Call Hold and Multiparty. Calls can be put on hold, recovered , released,
and added to a conversation.
Like for all Supplementary Services, the availability and detailed functi onality of Call Hold and Multiparty services
depends on the configuration of the GSM network. The MC55 can only re quest the service, but the network
decides whether and how the request will be answered.
Parameter Description
0 Release all held calls or set User Determined User Busy (UDUB) for a waiting
call:
• If a call is waiting, release the waiting call. The calling party will receive a
"BUSY" indication (Supplementary Service User Determined User Busy
"UDUB")
• Otherwise, terminate all held calls (if any).
1 Terminate all active calls (if any) and accept "the other call" as the active call:
• If a call is waiting, the waiting call will be accepted.
• Otherwise, if a held call is present, the held call becomes active.
Test Command
AT+CHLD=?
Response(s)
+CHLD: (list of supported <n>s)
OK
Write Command
AT+CHLD=[<n>]
Response(s)
OK
ERROR
+CME ERROR: <err>
PIN ASC0 ASC1 MUX1 MUX2 MUX3
% % % % % %
Reference(s)
GSM 07.07
<n>(num)