MC52i AT Command Set

MC52i AT Command Set
4.8 AT+CMUX
4.8 AT+CMUX Multiplex Mode
Multiplex mode according to GSM 07.10 and 3G TS 27.010 ([5]) enables the use of virtual channels set up over
one single serial interface. Every channel is used as an independent serial link. This way, up to three simultaneous
AT command sessions can be handled at a time. For example, the first channel can be used to send or
receive data, while two channels are available to control the module with AT commands or to establish a dedicated
channel to receive Unsolicited Result Codes (URC), e.g. "+CIEV:" or "RING".
MC52i incorporates an internal multiplexer and thus integrates all the functions needed to implement full-featured
multiplex solutions. For the application on top, customers have the flexibility to create their own multiplex programs
conforming to the multiplexer protocol. To help system integrators save the time and expense of designing
multiplexer applications, Cinterion Wireless Modules GmbH offers WinMux, a ready-to-use multiplex driver for
Windows XP, Windows Vista and Windows 7. Another approach is to develop customized solutions based on
the sources of the WinMux driver.
Refer to [4] which provides a detailed description of the multiplex architecture and step-by-step instructions of
how to install and configure the multiplex mode. The WinMux driver and its source files can be supplied on
request. Please contact your local distributor to obtain the latest installation software and user's guide.
All information provided in this section applies only to the ASC0 interface. The second interface ASC1 does not
support Multiplex mode and is not accessible when the multiplexer is started on ASC0. See also Section 1.9,
Auxiliary Serial Interface for details on ASC1.
AT+CMUX write command is used to enter Multiplex mode. Setup of the logical channels is initiated by the TE,
i.e. the TE acts as initiator. This means that the TE shall ensure that logical channels are established before any
further actions on the channels can be started. There is a timeout of five seconds, if the multiplexer protocol is
enabled but no multiplexer control channel is established. Afterwards MC52i returns to AT command mode.
The parameter maximum frame size (N1) according to GSM 07.10 is implemented as 98 bytes by default. All
other parameters are not available. Refer to [4] for further details regarding frame size.
Syntax
Test Command
AT+CMUX=?
Response(s)
+CMUX: (list of supporteds)
OK
Read Command
AT+CMUX?
Response(s)
+CMUX:
OK
ERROR
+CME ERROR:
Write Command
AT+CMUX=
Response(s)
OK
ERROR
+CME ERROR:
PIN ASC0 ASC1 MUX1 MUX2 MUX3 Charge Last Reference(s)
- + - - - - - - + GSM 07.07, GSM 07.10, 3GPP TS 27.010
MC52i_ATC_V01.201 Page 99 of 551 4/16/10
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