MUX State
B-2 AT Commands Reference Manual June 30, 2008
MUX State
Entry to state:
When the G24 receives the SABM0 frame.
Exit from state:
When the DTE requests the G24 to return to the PREMUX State.
Software Procedures Related to RS232 HW Lines

RI Hardware Line

PREMUX state: There is no change to the current RI line behavior.
MUX-Init state: The RI line becomes inactive.
MUX state: There is no change to the current RI line behavior.

DCD Hardware Line

In MUX and MUX-Init states, the DCD is always inactive. This line is not used within the MUX.

DTR Hardware Line

The procedure upon DTR interrupt is dependent on the AT&D settings in PREMUX state (GRLC
profile). In general, the DTR is always active.
If the PREMUX AT&D setting is 4 and the DTR is toggled while the G24 is in MUX or
MUX-INIT state, the G24 will return to PREMUX state. Upon its return, the G24 will release any
call (GPRS, CSD) except for a voice call.
Note: If the PREMUX AT&D setting was not 4, the G24 ignores the DTR without any
operation. The AT&D4 will be supported in future releases.

G24 DTR Interrupt

When G24 changes its state from PREMUX to MUX-Init, the G24 will disable the DTR interrupt
(since there is no need to use the DTR line) if its AT&D (of the GRLC profile) value is not 4.
When G24 changes its state to back to PREMUX, it re-enables its DTR interrupt.

DSR Hardware Line (Optional)

The DSR is always active in MUX state.