TC3x Multiplexer User's Guide
TC3x_UG_01_V03.10 -
Released
Page 10/50
10.01.2002
3 System Overview for the PC Mux
The multiplex mode allows to communicate with the module over one serial interface simultaneously
with 3 different customer applications (e.g. terminal programs). This is achieved by providing three vir-
tual channels using a multiplexer (Mux).
This is especially advantageous when a data call is ongoing. Without multiplexer no further access to
the module is possible without interrupting the data transfer. Using the multiplexer features like e.g.
controlling the module or using the SMS service can be done via the additional channels without dis-
turbing the data flow.
Furthermore, several accesses to the module can be created with the multiplexer, which is advanta-
geous when several independent electronic devices or interfaces are used.
3.1 Multiplexer Architecture when using the PC Mux
To make the three virtual interfaces (channels) available, both the TC3X module and the customer
application must contain Mux components which communicate over the Multiplexer Protocol. In the
TC3x module, the Mux/MP software is already incorporated. The customer application should either
integrate the TC3x Mux/MP software or include a Mux/MP developed by the customer.
3.2 Virtual Channels and AT commands
Generally take into account, that a module including the multiplexer does not include three different
devices, the module has only one single air interface, that means one RF part. The multiplexer simply
allows three simultaneous accesses to the module. So a call is never connected to a channel, but to
the device.
The functionality scope is alike for all logical channels except for the data calls. Channel 1 supports the
full range of functions, which is available without MP. Channel 2 and 3 are connected to a different AT
interpreter and support a subset of the functional range of channel 1.
Figure 1: Multiplexer architecture
Terminal programs
or internal programs
integrated in cus-
tomer application
platform
User
application
TC35
Channel 1
Channel 2
Channel 3
Terminal 1
Terminal 2
Terminal 3
MP
Data/Fax
Supported
Data/Fax
Not
Supported
Serial
I/O
MUX
conforming
to GSM 07.10
1
2
3
Serial
I/O
MUX
conforming
to GSM 07.10
