Technical information

Table Of Contents
Appendix B: MUX
January 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).