Siemens TC3 Series User manual

TC3x
Siemens Cellular Engines
Multiplex Mode
Installing,
Configuring,
Implementing
Version: V03.10
DocID: TC3x_UG_01_V03.10

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Document Name: TC3x Multiplexer User's Guide
Version: V03.10
Date: 10.01.2002
DocId: TC3x_UG_01_V03.10
Status: Released
General notes
With respect to any damages arising in connection with the described product or this document,
Siemens shall be liable according to the General Conditions on which the delivery of the described
product and this document are based.
This product is not intended for use in life support appliances, devices or systems where a malfunction
of the product can reasonably be expected to result in personal injury. Siemens AG customers using or
selling this product for use in such applications do so at their own risk and agree to fully indemnify
Siemens for any damages resulting from illegal use or resale.
Applications incorporating the described product must be designed to be in accordance with the
technical specifications provided in these guidelines. Failure to comply with any of the required
procedures can result in malfunctions or serious discrepancies in results.
Furthermore, all safety instructions regarding the use of mobile technical systems, including GSM
products, which also apply to cellular phones must be followed.
Handheld applications such as mobile phones or PDAs incorporating the described product must be in
accordance with the guidelines for human exposure to radio frequency energy. The Specific Absorption
Rate (SAR) of the application must be evaluated and approved to be compliant with national and
international safety standards or directives.
Subject to change without notice at any time.
Copyright notice
Copying of this document and giving it to others and the use or communication of the contents thereof,
are forbidden without express authority. Offenders are liable to the payment of damages. All rights
reserved in the event of grant of a patent or the registration of a utility model or design.
Copyright © Siemens AG 2002
Trademark notice
MS Windowsâis a registered trademark of Microsoft Corporation.

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Contents
1 Introduction.................................................................................................................................. 6
1.1 Supported product versions and related documents........................................................... 6
1.2 References .......................................................................................................................... 6
1.3 Abbreviations....................................................................................................................... 7
2 Technical Requirements for system with PC Mux ...................................................................8
2.1 System Software ................................................................................................................. 8
2.2 PC Multiplexer Simulation Software .................................................................................... 8
2.3 Hardware ............................................................................................................................. 8
2.3.1 Using virtual COM Ports....................................................................................... 8
2.3.2 Using physical COM Ports ................................................................................... 9
3 System Overview for the PC Mux ............................................................................................10
3.1 Multiplexer Architecture when using the PC Mux .............................................................. 10
3.2 Virtual Channels and AT commands................................................................................. 10
4 Installation of the components for the PC Mux...................................................................... 12
4.1 Hardware Installation......................................................................................................... 12
4.1.1 Using virtual COM Ports..................................................................................... 12
Using physical COM Ports................................................................................................. 12
4.2 PC Mux Software Installation ............................................................................................ 13
4.2.1 Multiplexer Simulation (PC Mux)........................................................................ 13
5 Using the PC Mux as external multiplexer ..............................................................................16
5.1 Starting the PC Mux ..........................................................................................................16
5.2 Stopping the PC Mux......................................................................................................... 18
5.3 Additional buttons of the PC Mux ...................................................................................... 19
5.4 Examples........................................................................................................................... 19
6 Internal work flow of the PC Mux............................................................................................. 22
6.1 Multiplexer Related Modules ............................................................................................. 23
6.1.1 Muxappl.exe with Pcmux.dll............................................................................... 23
6.1.2 Port.exe.............................................................................................................. 24
6.1.3 Controller.exe..................................................................................................... 24
6.1.4 Chopper.exe....................................................................................................... 25
6.1.5 Muxtester.exe..................................................................................................... 25
6.2 Additional Modules and Files............................................................................................. 25
6.2.1 Simulation.exe and Simulation.ini ...................................................................... 25
6.2.2 Log.exe .............................................................................................................. 25
6.2.3 Send.exe ............................................................................................................ 25
6.2.4 Process.exe ....................................................................................................... 25
6.2.5 Trace.exe ........................................................................................................... 26
6.3 The Internal Pipe System .................................................................................................. 26

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7 Integrating the multiplexer into the customer application .................................................... 27
7.1 Tips and Tricks .................................................................................................................. 27
7.1.1 Terminal Flow Control ........................................................................................ 27
7.1.2 Timeout after starting the multiplexer................................................................. 27
7.2 Restrictions........................................................................................................................ 27
7.3 Multiplexer control and signaling lines............................................................................... 28
7.3.1 Flow Control ....................................................................................................... 29
7.3.2 Escape Sequence .............................................................................................. 30
7.4 Power Saving .................................................................................................................... 30
7.5 Flash Management............................................................................................................ 30
8 Structure of the multiplexer protocol ...................................................................................... 31
8.1 Introduction of the multiplexer protocol .............................................................................31
Data link layer .............................................................................................................................. 31
8.2.1 Flag sequence.................................................................................................... 32
8.2.2 Address field ...................................................................................................... 32
8.2.3 Control field ........................................................................................................ 33
8.2.4 Length indicator.................................................................................................. 33
8.2.5 Information field ................................................................................................. 33
8.2.6 Frame checking sequence field (FCS) .............................................................. 33
8.3 State Diagrams.................................................................................................................. 34
8.3.1 Startup................................................................................................................ 37
8.3.2 DLC Establishment ............................................................................................ 38
8.3.3 Information transfer............................................................................................ 38
8.3.4 DLC release ....................................................................................................... 38
8.3.5 Closedown ......................................................................................................... 39
8.3.6 Multiplexer control channel ................................................................................ 39
8.3.6.1 Multiplexer close down (CLD) ............................................................................ 39
8.3.6.2 Test command (Test)......................................................................................... 40
8.3.6.3 Modem status command (MSC) ........................................................................ 40
8.3.6.4 Non-supported command response (NSC) ....................................................... 41
8.4 Samples of establishing logical channels.......................................................................... 41
8.4.1 Establishing logical channels without parameter negotiation............................. 41
8.4.2 Closing the multiplexer protocol and returning to AT mode ............................... 42
9 Version Control.......................................................................................................................... 43
9.1 Introduction........................................................................................................................ 43
9.2 Multiplexer versions........................................................................................................... 43
9.3 Implementation.................................................................................................................. 44
9.4 Case Descriptions ............................................................................................................. 45
9.4.1 Description case (01) ......................................................................................... 45
9.4.2 Description Case (02) ........................................................................................ 46
9.4.3 Description Case (03) ........................................................................................ 47
9.4.4 Description Case (04) ........................................................................................ 48
9.4.5 Abnormal Cases ................................................................................................ 48
9.5 Definitions.......................................................................................................................... 49
9.5.1 Coding of “TestCommand” message................................................................. 49
9.5.2 Example of “TestCommand” message .............................................................. 50

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Figures
Figure 1: Multiplexer architecture........................................................................................................... 10
Figure 2: Example configuration of the COM Ports when using virtual COM Ports............................... 12
Figure 3: Connection of the COM ports when using an 8 Port serial Card ............................................ 12
Figure 4: Simcominstall Tool.................................................................................................................. 13
Figure 5: Starting the multiplexer simulation.......................................................................................... 16
Figure 6: Start panel of the PC Mux....................................................................................................... 16
Figure 7: Starting the multiplexer in the PC Mux ................................................................................... 17
Figure 8: Start of the multiplexer in a terminal program......................................................................... 17
Figure 9: Multiplexer Simulation status field description ........................................................................ 18
Figure 10: Starting a multiplexer session............................................................................................... 19
Figure 11: Multiplexer activation on Hyperterminal ................................................................................ 20
Figure 12: Three active logical channels ............................................................................................... 21
Figure 13: Integration of the multiplexer ................................................................................................ 22
Figure 14: Flow control – RTS/CTS signaling........................................................................................ 29
Figure 15: Data link layer ....................................................................................................................... 31
Figure 16: Relationship between the customer µC and TC3X µC ......................................................... 35
Figure 17: MPl: Startup, DLC Establishment, Information Transfer....................................................... 36
Figure 18: MP: DLC Release, Close Down............................................................................................ 37
Figure 19: DLC Establishment ............................................................................................................... 38
Figure 20: Information transfer............................................................................................................... 38
Figure 21: DLC release.......................................................................................................................... 38
Figure 22: Multiplexer control channel ................................................................................................... 39
Figure 23: Modem status command (MSC)...........................................................................................40
Figure 24: Multiplexer control channel and logical channel, no parameter negotiation ......................... 42
Figure 25: Possible combinations for version check..............................................................................43
Tables
Table 1: Comparison of multiplexer channels........................................................................................ 11
Table 2: Available services if multiplexer is activated ............................................................................ 11
Table 3: Commands with possible channel dependencies ................................................................... 28
Table 4: Commands/Features without channel dependencies ............................................................. 28
Table 5: Address field ............................................................................................................................ 32
Table 6: Assignment of the DLCI ........................................................................................................... 32
Table 7: Use of the command/response bit ........................................................................................... 32
Table 8: Coding of the control field ........................................................................................................ 33
Table 9: Version cases .......................................................................................................................... 45
Table 10: IEI coding ............................................................................................................................... 49
Table 11: Coding of “TestCommand” (Example) ................................................................................... 50

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1 Introduction
The TC3x supports the basic option of the multiplex mode according to the ETSI TS 101 369, GSM
07.10 Multiplexer protocol and enables one physical serial interface to be partitioned into three virtual
channels. This allows you to take advantage of three simultaneous sessions running on one serial
interface. For example, you can send or receive data on the first channel, while the other two channels
are free to control the GSM engine with AT commands. In this document the multiplexer integration in
the module is also referred to as internal multiplexer.
Outside the module on the application side of the serial interface another multiplexer must be integra-
ted, in order to demultiplex the signal and distribute it on the 3 virtual channels. This external
multiplexer must be provided by the user.
For demonstration and test purposes a Windows program, the Multiplexer Simulation (PC Mux) is
available, which simulates the external multiplexer on a PC running with Windows NT. The multiplexer
protocol (MP) sources can be provided.
The purpose of this document is to describe how to install, configure and use the multiplexer in the
module as well as the Simulation of the multiplexer protocol (PC Mux) for Siemens TC3x GSM engines
and to explain how to integrate the external multiplexer in your application.
1.1 Supported product versions and related documents
Please note that this User Guide is intended for TC35 Version V03.10
Related documents
/1/ TC3x Hardware Interface Description V03.10
/2/ TC3x AT-Command-Set V03.10
/3/ Release Notes: TC3x, Version V03.10
/4/ Application Note: Updating TC3x Firmware V03.10
/5/ T35 Terminal Hardware Interface Description V03.10
/6/ TC35 MC35 Terminal User's Guide V03.10
Prior to using TC35 / TC35T or upgrading to a new firmware release, be sure to carefully read and
understand the latest product information provided in the Release Notes.
To visit the Siemens Website you can use the following link:
http://www.siemens.com/wm
1.2 References
[1] Digital Cellular Telecommunications Systems (Phase 2+); Terminal Equipment to Mobile Station
(TE-MS) "Multiplexer Protocol"; ETSI TS 101 369 V7.1.0 (1999-11), GSM 07.10 Version 7.1.0,
Release 1998
[2] AT Command Set – Siemens Cellular Engines; Version 03.10

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1.3 Abbreviations
CSD Circuit Switched Data
CTS Clear to Send
DCD Data Carrier Detect
DLCI Data Link Connection Identifier
DSB Developer Support Box
DSR Data Set Ready
DTR Data Terminal Ready
FC Flow Control
FFC Flat Flex Cable
GPRS General Packet Radio Service
GSM Global System of Mobile Communication
IEI Information Element Identifier
IP Internet Protocol
MO Mobile originated
MP Multiplexer Protocol
MS Mobile Station
MSDN Microsoft Developer Network
MT Mobile terminated
MUX Multiplexer
OS Operating System
PC Personal Computer
PC Mux Multiplexer Simulation
RTS Request to Send
TE Terminal Equipment
UART Universal Asynchronous Receiver Transmitter

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2 Technical Requirements for system with PC Mux
2.1 System Software
•Windows NT4.0
This requirement only refers to PC Mux software which we provide for testing purposes. It has been
developed for Windows NT 4.0. Of course the multiplexer protocol can be implemented in any OS.
2.2 PC Multiplexer Simulation Software
In order to use the PC Mux, you get a *.zip file, which includes files to install the PC Multiplexer Simula-
tion Program on your PC.
The PC Mux is a Windows NT program, which enables the usage of the external multiplexer on a PC.
This program is a suitable means to demonstrate and make use of the functionality of the multiplexer
during the development phase. Only the binary versions of the PC Mux files will be provided.
Provided files:
When you extract the *.zip file the following files will be extracted onto your PC:
•chopper.exe
•controller.exe
•log.exe
•muxappl.exe
•muxport.exe
•muxtester.exe
•pcmux.dll
•process.exe
•send.exe
•sharecnt.dll
•simcom.sys
•simcominstall.xls
•simulation.exe
•simulation.ini
•trace.exe
The file pcmux.dll includes all *.c and *.h files, which form the multiplexer protocol. They must be inte-
grated in the module software as well as on the PC side. Refer to chapter 6.1 for detailed information
about the purpose of each file.
2.3 Hardware
•Minimum Pentium III, 133 Mhz
•e.g. DSB35 or TC35T (during development or testing phase)
•TC35 module with baud rate set to 57600 bps
2.3.1 Using virtual COM Ports
•1 RS232 interface
•1 RS232 cable

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2.3.2 Using physical COM Ports
•7 RS232 interfaces (e.g. 1 Serial 8 Port expansion card)
•3 null modem RS232 cables
•1 RS232 cable

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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

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Table 1 shows which features are available on each channel.
Voice calls
incoming/outgoing
Data calls
incoming/outgoing
SMS
incoming
/outgoing
Phonebook
management
AT
commands
Channel 1 lllll
Channel 2, 3 l--- lll1)
lindicates that the functionality is available on the channel
--- indicates that the functionality is not available on the channel
1) except for AT commands related to data
Examples:
•While a data call is in progress on channel 1, you can send an SMS on channel 2 and edit the
phonebook on channel 3. The last access is the deciding one. When writing the same phonebook
entry simultaneously on two different channels, the one writing last, is the one which will be perma-
nent. The others will be lost.
•AT&V shows less settings when executed on channels 2 and/or 3 than on channel 1.
•AT+CMGF can be configured separately for each channel.
Note:
Data and voice calls are not possible simultaneously, because of the single air interface. For further
restrictions of the multiplexer mode please refer to [2] supplied with TC3x.
The following table points out the main differences using the module with and without multiplexer:
Multiplexer activated
Logical channel 1 2 3
Mode ATC and Data ATC ATC
The applications which access the module, must avoid mutual disturbances. They should know about
each other´s functionality.
For further details regarding restrictions and interferences between the channels see also chapter 7.2.
Table 1: Comparison of multiplexer channels
Table 2: Available services if multiplexer is activated

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4 Installation of the components for the PC Mux
4.1 Hardware Installation
The following chapters describe the two different possibilities how to realize the physical connection
from the application (PC) to the module.
4.1.1 Using virtual COM Ports
Creating virtual COM ports avoids the installation of 7 COM ports (8 Port serial card) in your PC. The
applications (e.g. terminal programs) must be connected to the 3 virtual COM Ports. The multiplexer
internally connects these 3 Ports to 3 other virtual Ports and maps them onto the one serial Port which
is physically connected to the DSB35 or TC35T. See chapter 4.2.1 to install the virtual ports.
Figure 2: Example configuration of the COM Ports when using virtual COM Ports
Note:
When using virtual COM Ports RTS/CTS are not passed to the application. So data transfer is not
possible.
4.1.2 Using physical COM Ports
Figure 3: Connection of the COM ports when using an 8 Port serial Card
virtual COM ports
COM14
COM15
COM16
COM24
COM25
COM26
COM1
multiplex
simulation
controller
multiplex
HyperTerminal
HyperTerminal
HyperTerminal DSB35 or
T
C35
T
COM 1
COM 2
COM 3
COM 4
COM 5
COM 6
COM 7
COM 8
PC
Terminal
Program
Terminal
Program
Terminal
Program
FFC
Null Modem Cables
Serial Cable
DSB35
DSub9 Application
Interface
MP

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Install the 7 COM ports (8 Port serial card) in your PC. Some systems may show problems and not all
cards may be compatible with your system. The 8 Port serial card in your PC allows the usage of
physical ports for the applications. The applications (e.g. terminal programs) must be connected to 3 of
the 7 physical COM Ports. Connect these 3 Ports with 3 other Ports of the serial card with null modem
cables (see Figure 3). The multiplexer internally maps these 3 Ports to the one serial Port which is
physically connected to the DSB35 or TC35T.
4.2 PC Mux Software Installation
4.2.1 Multiplexer Simulation (PC Mux)
Note:
Attention: The multiplexer simulation only runs on Microsoft Windows NT 4.0 operating systems!
1. Create a directory on your hard disk were to save the files or use an existing directory and copy the
installation files to your hard disk (further steps are done in the hard disk directory).
2. Remove the write protection from all files.
Steps 3 to 5 are only relevant when using virtual COM Ports. Otherwise proceed with step 6.
3. Change to directory ../simcom
4. Open the Excel file simcominstall.xls and follow the steps to install the virtual COM ports. Figure 4
shows an example of how to install the virtual COM Ports. Choose the Port numbers according to
your system configuration. With the Remove button the COM Ports can be deinstalled again.
5. Reboot the system
6. Open the file simulation.ini in a text editor and adapt the numbers and baudrate in the sections
CHANNEL0, CHANNEL1, CHANNEL2 and CHANNEL3 to your system configuration as described
below. PC Mux requires 1 physical and 3 virtual or physical (when using 7 COM ports) COM ports.
Figure 4: Simcominstall Tool

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•Section CHANNEL0
This section contains the configuration of the physical COM port your DSB35 or TC35T is
connected to. You may modify the selected Port and the Baud rate. When using all 3 virtual
channels, we recommend you use a baud rate of 57600 bps (AT+IPR=57600<CR><LF>).
Note:
Autobauding must be turned off!
Example for the physical channel:
[CHANNEL0]
; type specifies the executable to start
Type=PORT
; own server name
Name=hardware
; default destination [CONTROL]
Destination=ctrl
; serial interface
Port=COM1
Baud=57600
DataBits=8
; parity: 0=no, 1=odd, 2=even, 3=mark, 4=space
Parity=0
; stop bits: 0=1, 1=1.5, 2=2
StopBits=0
•Sections CHANNEL1 to CHANNEL3
These sections contain the configuration of the 3 virtual (or physical) COM ports. As above you
may modify the Port and Baud settings. A baud rate of 19200 bps is sufficient, but 57600 are
recommended. The baud rate setting has no impact on the virtual COM Ports, but is only
relevant when using physical ports.
Example for the first logical channel:
[CHANNEL1]
; type specifies the executable to start
Type=PORT
; own server name
Name=channel1
; default destination [CONTROL]
Destination=ctrl
; serial interface
Port=COM24
Baud=57600
DataBits=8
; parity: 0=no, 1=odd, 2=even, 3=mark, 4=space
Parity=0
; stop bits: 0=1, 1=1.5, 2=2
StopBits=0

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Example for the second logical channel:
[CHANNEL2]
; type specifies the executable to start
Type=PORT
; own server name
Name=channel1
; default destination [CONTROL]
Destination=ctrl
; serial interface
Port=COM25
Baud=57600
DataBits=8
; parity: 0=no, 1=odd, 2=even, 3=mark, 4=space
Parity=0
; stop bits: 0=1, 1=1.5, 2=2
StopBits=0
Example for the third logical channel:
[CHANNEL3]
; type specifies the executable to start
Type=PORT
; own server name
Name=channel1
; default destination [CONTROL]
Destination=ctrl
; serial interface
Port=COM26
Baud=57600
DataBits=8
; parity: 0=no, 1=odd, 2=even, 3=mark, 4=space
Parity=0
; stop bits: 0=1, 1=1.5, 2=2
StopBits=0
Note:
The examples given assume that virtual COM Ports have been installed. Instead of COM24 you
may connect any other virtual channel or physical channel (when using 7 COM ports). The
sections for CHANNEL2 and CHANNEL3 need to be filled out accordingly.
Now all hardware and software components have been installed and you can work with the PC Mux.

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5 Using the PC Mux as external multiplexer
The PC Mux simulates the multiplexer on a PC and can be used as an external multiplexer. However,
this requires some configuration as described in the following chapters.
Note:
The usage of the multiplexer is not possible, when auto bauding (AT+IPR) has been activated.
5.1 Starting the PC Mux
Start the PC Mux by double clicking the file simulation.exe.
The Multiplexer
Simulation window as in
Figure 6 pops up on your
screen.
Click Enable Display (1)
in order to trace the MP
output on your display.
Note:
Only use the display
when not in data mode,
because it takes away too
many resources.
When clicking on Start
(2), the virtual ports are
initialized (terminals can
be connected), but the
module is not yet in
multiplexer mode.
Figure 5: Starting the multiplexer simulation
Figure 6: Start panel of the PC Mux

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There are two ways to start
the multiplexer:
A. Follow the steps
highlighted in Figure 7:
•(1) Choose Enable
Multiplexer from the
Combo Box menu of
the PC Mux window
•(2) Click on the button
Send
•(3) If you have en-
abled the display, the
last status message
should indicate that
the multiplexer has
been enabled
successfully
Note:
In the unsuccessful case,
the PC Mux does not start
and after a timeout after 5s
the normal AT interface is
started.
B. When switching on the module after a firmware update, we recommend to wait 5 seconds before
entering AT commands. Enter AT+CMUX=0<CR><LF> in a terminal program connected to the
first logical channel. See also Figure 8.
Approximately one second later the module is in multiplex mode.
Note:
No ATC-response traffic must be ongoing on any of the three logical channels when switching off the
multiplexer.
To check whether the PC Mux is operational, enter a short AT command on each of the three terminal
programs and verify whether the module sends a correct response.
The Status window shows the debug output of the MP sources. A log-file trace.txt which is created in
the same directory as the simulation.exe, contains the whole output. See Figure 9 for explanation of
the Multiplexer Simulation buttons.
Figure 7: Starting the multiplexer in the PC Mux
Figure 8: Start of the multiplexer in a terminal program

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When PC Mux is in service, it disposes of the 4 COM Ports which have been defined in simulation.ini
and no other application can use them.
5.2 Stopping the PC Mux
To stop the multiplex mode, choose Disable Multiplexer from the Combo Box of the Multiplexer
Simulation. Click on Send. See Figure 9.
This switches the module back to Normal Mode. The RS232 interface of the module is now connected
to the first logical channel.
Note:
No ATC-response traffic must be ongoing on any of the three logical channels when switching off the
multiplexer.
Clicking on Stop frees the COM Ports and PC Mux can be terminated. You can use the COM Port
which is connected to the module e.g. for starting a terminal program.
It is crucial that PC Mux be terminated as described above. If you terminate the PC Mux or switch off
the PC while the multiplexer mode is still active, the module stays in the multiplexer mode. PC Mux is
not able to synchronize with a running Mux protocol, so that the module must be restarted.
Figure 9: Multiplexer Simulation status field description

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5.3 Additional buttons of the PC Mux
In addition to the functions already described the PC Mux has a display and a trace possibility.
With Enable Display/Disable Display the running Mux protocol can be displayed in the status win-
dow. When activating the display before starting the Mux, error messages e.g. for wrong configuration
of the simulation.ini are displayed. Choose Enable/Disable Trace to output results into the file
trace.txt.
Note:
The file may become quite big.
5.4 Examples
Figure 10 shows how to start a multiplexer session. First start the multiplexer simulation by double
clicking on the simulation.exe (1). Then start the terminal programs one after another (2-4). Make sure
that the terminal programs are connected to the correct logical COM Ports. Now enter AT+IPR to set
the baud rate.
Afterwards start the multiplexer with AT+CMUX=0 as shown in Figure 11.
Figure 10: Starting a multiplexer session

TC3x Multiplexer User's Guide
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Figure 11: Multiplexer activation on Hyperterminal
With AT+CMUX=0 the multiplexer has been activated. Now all terminals can be used. Figure 12 shows
that all terminals are ready to process AT commands.