Motorola G24 Benutzerhandbuch

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Appendix B: MUX
 December  31, 2007
AT Commands Reference Manual
B-3
MUX UART Port Speed 
Auto baud rate detection is disabled in the MUX. To set the UART baud rate, the G24 uses the 
<port speed> parameter in +CMUX command. If the parameter is absent, the MUX uses the same 
baud rate that was in PREMUX state.
Controlling the UART Port Speed Within MUX State 
AT commands such as +CBAUD and +IPR change the virtual baud rate of an IDLC. The 
AT+CBAUD? or AT+IPR? commands display the virtual baud rate of the specific IDLC. The 
AT+CMUX? command returns the UART baud rate.
Basic Mode UART Software Flow Control 
When the G24 enters MUX state or MUX-Init state and the requested mode is Basic, UART 
software flow control is disabled. If the AT&K command is set for software flow control, the G24 
RS232 serial manager ignores the XON/XOFF characters. When the G24 returns to PREMUX 
state, it reads the GRS232CFG AT&K value and acts accordingly.
Advanced Mode UART Software Flow Control 
When the G24 enters MUX-Init state and the requested mode is Advanced, UART software flow 
control can be used. The G24 acts according to the AT&K value.
Advanced mode ensures that unplanned XOFF/XON characters are not passed inside the MUX 
frames by the transparency mechanism. 
If the MUX mode is Advanced and AT&K is set for software flow control, the XON/XOFF 
characters are detected and removed from the lower layers (UART, serial manager).
Basic Mode MUX Software Flow Control Per Channel
When G24 enters MUX state and the requested mode is Basic, Software Flow Control Per 
Channel is enabled.
When G24 MUX virtual channel is not able to receive data, it sends the appropriate MSC 
command (according to 3G TS 27.010 V3.3.0), that contains the number of virtual channel that 
not able to receive data. If terminal continues to send data to that virtual channel, G24 will buffer 
incoming data and deassert CTS (hardware flow control) when the buffer is full.
When G24 MUX virtual channel is ready and able to receive data, it sends the appropriate MSC 
command (according to 3G TS 27.010 V3.3.0), that contains the number of virtual channel that 
ready to receive data.
If the terminal is not able to receive data (typically because its receive buffer is almost full), it 
sends the appropriate MSC command (according to 3G TS 27.010 V3.3.0) with the number of 
virtual channel, that not able to receive data. In this case, G24 stops to send data at appropriate 
virtual channel. When the terminal is ready and able to receive data, it sends the appropriate MSC 
command to G24 (according to 3G TS 27.010 V3.3.0) with the number of virtual channel, to 
indicate this.