GT863-3GG Product Description
80269ST10077a Rev.0
–
2010-09-22
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved.
Page 27 of 37
7.2.
CMUX
CMUX (Converter-Multiplexer) is a multiplexing protocol implemented in the Telit
module that can be used to send any data, SMS, fax, TCP data.
7.2.1.
Product architecture
The Multiplexer mode enables one serial interface to transmit data to four different
customer applications. This is achieved by providing four virtual channels using a
Multiplexer (Mux).
This is especially advantageous when a fax/data/GPRS call is ongoing. Using the
Multiplexer features, e.g. controlling the module or using the SMS service can be
done via the additional channels without disturbing the data flow; access to the
second UART is not necessary.
Furthermore, several accesses to the module can be created with the Multiplexer.
This is of great advantage when several independent electronic devices or interfaces
are used.
To access the three virtual interfaces, both the GSM engine and the customer
application must contain Mux components, which communicate over the multiplexer
protocol.
In Multiplexer mode, AT commands and data are encapsulated into packets. Each
packet has channel identification and may vary in length.
7.2.2.
Implementation feature and limitation
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7.10 CMUX Basic Option used
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CMUX implementation support four full DLCI (Serial Port)
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Every CMUX instance has its own user profile storage in NVM
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Independent setting of unsolicited message.
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Every CMUX instance has its own independent flow control
NOTE: More details about the Multiplexer mode are available in the Cmux Product
Specification
