TC3x Multiplexer User's Guide
TC3x_UG_01_V03.10 -
Released
Page 27/50
10.01.2002
7 Integrating the multiplexer into the customer application
If you want to make your own design of the multiplexer, you may use the delivered sources. You get a
*.zip file, which includes
files you can use to include the multiplexer in your application. Naturally you
may instead make your own implementation of the multiplexer.
Provided files:
When you extract the *.zip file *.c and *.h files will be installed on your PC. You need to link and
compile these files together with your application software. Refer to chapter 6.1 for detailed information
about the purpose of each file.
7.1 Tips and Tricks
7.1.1 Terminal Flow Control
The Multiplexer Simulation provides RTS/CTS hardware flow control. If a terminal application uses
toggle flow control (this includes Start/Stop of the Application), the Multiplexer Simulation informs the
module about this. This way an unintended blocking may occur:
Example:
An application may set RTS when being started and resets RTS when being closed (e.g. Hyper-
Terminal uses RTS this way, regardless of the flow control settings). The Multiplexer Simulation de-
tects the toggling of RTS and informs the module. If another applications is started on this serial port,
which does not set RTS (e.g. ZOC uses RTS this way, if RTS/CTS-handshake is not activated by de-
fault), it cannot send/receive data from then Multiplexer Simulation until it toggles the RTS-line to High.
The following procedure is recommended to change from flow control to none flow control follow the
steps listed below:
1. Flow control is switched on
2. Disable Multiplexer (Choose
Disable Multiplexer
and push button
Send
)
3. Switch off flow control within the terminal
4. Start Multiplexer again (e.g. AT+CMUX=0)
This procedure is absolutely necessary, otherwise a restart of the whole environment (GSM engine and
Multiplexer simulation) is required.
7.1.2 Timeout after starting the multiplexer
Bear in mind that a 5 second timeout should be kept after starting the multiplexer. No AT commands
should be entered. If the multiplexer does not start correctly, the normal AT interface will be freed again
after the timeout.
7.2 Restrictions
•
After starting the MUX-Protocol 3 logical channels are available. Beware of the following restric-
tions:
•
The TC3x supports the basic option and UIH Framing according to GSM 07.10.
•
MO and MT Data calls can only be set up on channel 1
•
It is not possible to set up a data and a voice call on channel 1 at the same time.
•
Unsolicited Result Codes will generally be transmitted to all logical channels (like “RING”).
•
In charge-only and in alarm mode the multiplexer is not available
•
See [2] for multiplexer characteristics with the commands AT&V, AT+CNMI, +CALA and +CMEE
