AT Command Set

4.28 AT+CMUX Enter multiplex mode

MC35 supports Multiplex mode according to the GSM 07.10 Multiplexer Protocol and enables one physical serial asynchronous interface to be partitioned into three virtual channels. This allows you to take advantage of up to 3 simultaneous sessions running on the serial interface. Each session represents a stream of bytes conveying various data; such as voice, fax, data, SMS, phonebook in- formation, battery status etc. For example, you can transfer data over one channel while two further channels are free to control the GSM engine with AT commands. It should be noted, however, that voice, data, fax or GPRS calls cannot be established simultaneously, since the mobile device pro- vides just one air interface to the network.

To make the three virtual interfaces (channels) available, both the MC35 module and the customer application must contain Mux components which communicate over the Multiplexer Protocol. In the MC35 module, the Mux/MP software is already incorporated. The customer application should either integrate the MC35 Mux/MP software or include a Mux/MP program developed by the customer. The AT+CMUX write command starts the multiplexing protocol control channel.

Refer to [5] which provides to a detailed description of the Multiplex functionality implemented in MC35 and step-by-step instructions of how to install and configure the MUX mode. The source files of the MC35 Mux/MP software can be supplied on request. Please contact your local dealer to ob- tain the latest installation software and user's guide.

Test command

Response

AT+CMUX=?

+CMUX: (list of supported <mode>s) OK

 

 

Read command

Response

AT+CMUX?

+CMUX: <mode> OK

 

If error is related to ME functionality:

 

+CME ERROR: <err>

 

 

Write command

Response

AT+CMUX=<mode>

OK

 

If error is related to ME functionality:

 

+CME ERROR: <err>

Parameter

<mode> multiplexer transparency mechanism

0basic option

Subparameters defined in GSM07.07 are adjusted for control and logical channels as follows:

<subset>

0

UIH frames used only (control channel)

Reference

GSM 07.07

Note

1.The write command is used to enter the multiplex mode. The 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 estab- lished before any further actions on the channels can be started.

2.There is a timeout of five seconds, if the multiplexer protocol is enabled and no multiplexer control channel is established. The GSM engine re-

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Siemens MC35 28 AT+CMUX Enter multiplex mode, +CMUX list of supported modes OK, If error is related to ME functionality
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MC35 specifications

The Siemens MC35 is a compact and versatile modem designed primarily for mobile communication, data transmission, and machine-to-machine (M2M) applications. Launched in the early 2000s, it quickly became popular due to its blend of performance, reliability, and ease of integration, making it a solid choice for developers and businesses.

One of the key features of the MC35 is its support for GSM and GPRS technologies. This allows it to connect seamlessly to various networks, enabling users to transmit data at speeds that were impressive for its time. The GPRS capability can offer data rates of up to 171.2 kbps, allowing for efficient data transfer even in areas with limited connectivity.

The MC35 is designed to support both SMS and voice functionalities, making it adaptable for a range of applications. This includes remote monitoring, telemetry, and alarm signaling. The ability to send and receive SMS messages is a significant advantage for applications that require immediate alerts and notifications, enhancing its utility in security systems and industrial automation.

Furthermore, the modem is equipped with a range of interfaces, including serial communication (RS232), which makes it compatible with various hardware devices. This facilitates easy integration into existing systems, whether for industrial machinery or consumer electronics. Additionally, it features a robust software development kit (SDK), which enables developers to create custom applications tailored to their specific requirements.

Power consumption is another notable characteristic of the Siemens MC35. It is engineered to be energy-efficient, which is especially important for battery-operated devices or systems that require a prolonged operation without frequent recharging or maintenance.

In terms of physical characteristics, the MC35 is compact and lightweight, allowing it to fit into various enclosure designs without occupying much space. Its durability ensures it can perform reliably in different environments, making it suitable for outdoor and industrial applications.

To summarize, the Siemens MC35 stands out as a reliable modem with a rich feature set that includes GSM and GPRS support, SMS and voice capabilities, easy integration through various interface options, and energy-efficient operation. Its adaptability makes it a valuable tool for a wide array of communication and data transmission tasks, solidifying its place in the evolution of mobile communications technology.
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