Siemens Mux_guide_v06 - Manual (Page 3)

Multiplexer User's Guide
Confidential / Released
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Mux_guide_v06 Page 3 of 36 30.06.2004
Contents
0 Document history..........................................................................................................5
1 Introduction ...................................................................................................................6
1.1 Supported products and related documents..........................................................7
1.2 References ............................................................................................................7
1.3 Term and abbreviations .........................................................................................8
2 Multiplexer protocol – an overview .............................................................................9
2.1 Product concept and architecture ..........................................................................9
2.2 Virtual channels and AT commands ....................................................................10
3 Integrating multiplexer into the customer application ............................................11
3.1 Characteristics .....................................................................................................11
3.1.1 Basic requirements ................................................................................11
3.1.2 Restrictions ............................................................................................11
3.1.3 Dependencies between multiplexer channels and restrictions of use ...12
3.1.4 Functions without channel dependencies..............................................12
3.1.5 Timing conditions ...................................................................................13
3.1.6 Operation of a second physical serial interface ASC1 (if applicable) ....13
3.2 Multiplexer control and signaling lines .................................................................14
3.2.1 Flow control............................................................................................14
3.2.2 Escape sequence ..................................................................................16
3.3 Power saving .......................................................................................................16
3.4 Bandwidth of logical channels .............................................................................16
4 Structure of the multiplexer protocol........................................................................17
4.1 Introduction of the multiplexer protocol................................................................17
4.2 Data link layer ......................................................................................................17
4.2.1 Flag sequence .......................................................................................18
4.2.2 Address field ..........................................................................................18
4.2.3 Control field............................................................................................19
4.2.4 Length indicator .....................................................................................20
4.2.5 Information field .....................................................................................20
4.2.6 Frame checking sequence field (FCS)...................................................20
4.3 State diagrams.....................................................................................................21
4.3.1 Start-up procedure .................................................................................25
4.3.2 DLC establishment.................................................................................25
4.3.3 Information transfer................................................................................25
4.3.4 DLC release ...........................................................................................26
4.3.5 Close-down procedure...........................................................................26
4.3.6 Multiplexer control channel ....................................................................26
4.3.7 Multiplexer close down (CLD) ................................................................27
4.3.8 Test command (Test).............................................................................27
4.3.9 Modem status command (MSC) ............................................................28
4.3.10 Power saving control (PSC)...................................................................30
4.3.11 Non-supported command response (NSC)............................................31
4.4 Example: Establishing logical channels without parameter negotiation ..............32