Multiplexer User's Guide
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4.4Example: Establishing logical channels without parameter negotiation
•Send AT+CMUX=0; wait for the response
•Send Request SABM for DLCI = 0; wait for the response
•Send Request SABM for all requested DLCIs; wait for the response
As a result the multiplexer is established and information / data can be transmitted (⇒ ready for Information Transfer).
| Serial |
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| interface |
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Customer | GSM engine µC |
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µC |
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Closed Down | Closed Down |
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RequestStartUp | IndicationStartUp | Start Up | "AT+CMUX" | |
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ConfirmStartUp | ResponseStartUp | |||
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Disconnected | Disconnected |
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Disconnected | Disconnected |
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DLCI = 0 | DLCI = 0 |
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RequestSABM | IndicationSABM | DLC Establishment, | Create DLCI = 0 | |
DLCI = 0 | ||||
DLCI = 0 | ||||
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ConfirmUA | ResponseUA | |||
DLCI = 0 | ||||
DLCI = 0 |
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Connected | Connected |
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DLCI = 0 | DLCI = 0 |
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Disconnected | Disconnected |
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DLCI = 1 | DLCI = 1 |
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RequestSABM | IndicationSABM | DLC Establishment, | Create DLCI = 1 | |
DLCI = 1 | ||||
DLCI = 1 | ||||
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ConfirmUA | ResponseUA | |||
DLCI = 1 | ||||
DLCI = 1 |
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Connected | Connected |
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DLCI = 1 | DLCI = 1 |
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Figure 13: Establishing the multiplexer control channel and the logical channel
Mux_guide_v06 | Page 32 of 36 | 30.06.2004 |
