Motorola G24 用户手册

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页码 642
RS232 Multiplexer Feature
3-440
 AT Commands Reference Manual
December  31, 2007
MUX Customer Open Source Code Packet
The MUX is provided with an open source code packet to help speed the development process 
and reduce the incompatible interpretations of the protocol specifications. This source code 
packet is saved in the VOBS and supports both Basic and Advanced modes.
When implementing the MUX feature, the user should have the MUX entity installed with the 
product. The following two MUX integration options are available to the user:
MIP (Mux Integration Packet): The user receives the source code, which is provided by 
Motorola, with known APIs for the MUX. The MIP is a Motorola open source code packet 
for the GSM 27.010 protocol with API functions provided for the user.
MUI (Mux User Implementation): The GSM 27.010 protocol is implemented by the user. 
The MUI is the user implementation device for the GSM 27.010 protocol.
APIs
There are five API user integrations, as follows:
Open service
Close service
Sending Data service
Receiving Data service
MUX service test, MSC, FC and so on (refers only to the control channel)
MUX Channels (Information Data Link Control - IDLC)
The following sections describe the MUX channels.
Basic MUX Channel Definitions
Each MUX channel functions as a regular RS232 connection that follows ETSI 07.07 and 
ITU V.25 standards. However, there are some limitations, as described in this paragraph.
The G24 IDLC channel switches to Data mode as specified in ETSI 07.07 [4].
When the MUX protocol layer releases the IDLC channel, any GPRS/DATA session or 
established call is hung up. Only active voice calls remain connected.
AT command requests by an IDLC may result in an ERROR, while in PREMUX state the 
same request would never have returned an ERROR. This may happen because the addressed 
resource in the G24 is busy with a second IDLC request. For example, if two channels send 
the AT+CLIP? command, which addresses the GSM engine, only one channel receives the 
+CLIP: response, while the other receives an ERROR.
Channel Priorities
The control channel has the highest priority. All other IDLCs have the same priority.
Note:
All control frames are processed before any other channels. IDLC frame validation is also 
performed after all control frames are processed.