Siemens Mux_guide_v06 manual Functions without channel dependencies

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Multiplexer User's Guide

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3.1.3 Dependencies between multiplexer channels and restrictions of use

When using the following functions, be aware of possible dependencies between the different channels. One way of avoiding problems may be to dedicate certain commands/features to one of the channels or to assure that the application avoids conflicts.

Call control: A voice call can be initiated, answered or ended on each channel. See AT commands like ATD, ATA or ATH.

Please note that ATH terminates each voice, circuit switched data or fax call regardless on which logical channel ATH was executed, for details see [2].

Phonebook access: If you wish to write the same phonebook entry on two different channels at the same time, please note that the last entry will be stored permanently. All other data will be deleted.

SMS read, write and delete.

Time settings: Though the AT commands AT+CALA and AT+CCLK can be used on either channel, the same time setting applies to all three channels. It is only the alarm message <text> which may be specific to each channel. The URC “+CALA” will be issued only on the channel where the last alarm setting was made. For details see [2].

Device locks set with AT+CLCK.

SIM card access.

RF settings.

Example:

An ongoing fax call has been established on channel 1. When answering an incoming voice call on channel 2 or 3 and terminating it, the held fax call will be ended as well.

3.1.4 Functions without channel dependencies

The following functions or events may be ongoing independently on different channels:

Unsolicited Result Codes (URCs) will generally be transmitted to all logical channels. For example, an incoming voice call is indicated by the URC “RING” on all three channels. Incoming data calls are indicated on channel 1 only.

Device information can be queried on a single channel.

Signal quality and cell information can be retrieved on a single channel.

Further commands that can be used separately on one channel without impact on the remaining channels: ATZ, AT&F, AT&V, AT+CEER, AT+CMEE.

User profile: AT&W stores the current setting of each channel to the user profile, no matter on which of the three channels the command is executed.

Example:

The battery capacity can be queried from channel 2 or 3 while a voice, fax or data call is made on channel 1.

Mux_guide_v06

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Contents Version DocID Muxguidev06 Siemens Cellular EnginesDocument Name Multiplexer Users Guide Multiplexer Users GuideJune 30 Muxguidev06Contents Tables Multiplexer protocol version controlChapter What is new Document historyIntroduction Supported products and related documents ReferencesTerm and abbreviations Abbreviation DescriptionMultiplexer protocol an overview Product concept and architectureVirtual channels and AT commands Characteristics Integrating multiplexer into the customer applicationBasic requirements RestrictionsFunctions without channel dependencies Timing conditions Multiplexer control and signaling lines Flow controlLogical flow control RTS/CTS on the physical channelsRTS/CTS on the logical channels COM M COM N COM P RTS/CTSPower saving Bandwidth of logical channelsEscape sequence Structure of the multiplexer protocol Introduction of the multiplexer protocolData link layer Flag sequence Address fieldControl field Frame TypeLength indicator Information fieldFrame checking sequence field FCS BitState diagrams Relationship between the customer µC and the GSM engine µC Serial Interface Customer GSM engine AT+CMUXSerial interface Customer µCCustomer EngineGSM engine ResponderClose-down procedure DLC releaseMultiplexer control channel Type fieldTest command Test Multiplexer close down CLDLength field Modem status command MSC Break signal optional Bit Not supported Power saving control PSC Commands Bit DescriptionType Bit Value octet Length=1 BitNon-supported command response NSC Value octet Bit Command TypeNon-supported command No Value octet Length=0Customer GSM engine µC AT+CMUXMultiplexer protocol version control IntroductionModem status command MSC Signals Break Signals Octet Optional Command BitSignals Bit Multiplexer protocol versionsTroubleshooting Implementing version controlCoding of TestCommand message Example of TestCommand message