Siemens Mux_guide_v06 manual Multiplexer protocol version control, Introduction

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Multiplexer User's Guide

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5 Multiplexer protocol version control

5.1 Introduction

The multiplexer protocol offers a version control to ensure that TE and MS support the same extent of functionality and to maintain upward and downward compatibility when later firmware versions of the GSM engines are released. The implementation of version control is a subset of the GSM 07.10 standards.

When the multiplexer is started, the MS and the application negotiate which MP version to use. If TE and MS do not support the same multiplexer protocol, the lower version will be agreed upon. If no version check is done the TE reverts, due to lack of version information, to multiplexer version 1. This means that both sides only agree on version 1, even though they may have the same and even higher version.

The TE and MS multiplexer version numbers can be traced on the serial interface. They appear as follows:

TE version (e.g. version 1): TEMUXVERSION0001

MS version (e.g. version 2): MSMUXVERSION0002

In multiplexer protocol sources delivered by Siemens AG version control is integrated. When designing an application based on other sources take care to implement the version check as well, especially if you wish to upgrade to later firmware releases. It is strongly recommended to implement the latest multiplexer version available.

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Contents Siemens Cellular Engines Version DocID Muxguidev06Multiplexer Users Guide Document Name Multiplexer Users GuideJune 30 Muxguidev06Contents Multiplexer protocol version control TablesDocument history Chapter What is newIntroduction References Supported products and related documentsAbbreviation Description Term and abbreviationsProduct concept and architecture Multiplexer protocol an overviewVirtual channels and AT commands Integrating multiplexer into the customer application CharacteristicsBasic requirements RestrictionsFunctions without channel dependencies Timing conditions Flow control Multiplexer control and signaling linesLogical flow control RTS/CTS on the physical channelsCOM M COM N COM P RTS/CTS RTS/CTS on the logical channelsPower saving Bandwidth of logical channelsEscape sequence Structure of the multiplexer protocol Introduction of the multiplexer protocolData link layer Address field Flag sequenceFrame Type Control fieldInformation field Length indicatorFrame checking sequence field FCS BitState diagrams Relationship between the customer µC and the GSM engine µC AT+CMUX Serial Interface Customer GSM engineCustomer µC Serial interfaceEngine CustomerGSM engine ResponderDLC release Close-down procedureMultiplexer control channel Type fieldTest command Test Multiplexer close down CLDLength field Modem status command MSC Break signal optional Bit Not supported Commands Bit Description Power saving control PSCType Bit Value octet Length=1 BitValue octet Bit Command Type Non-supported command response NSCNon-supported command No Value octet Length=0AT+CMUX Customer GSM engine µCIntroduction Multiplexer protocol version controlSignals Break Signals Octet Optional Command Bit Modem status command MSCSignals Bit Multiplexer protocol versionsImplementing version control TroubleshootingExample of TestCommand message Coding of TestCommand message