RS232 Multiplexer Feature
3-444 AT Commands Reference Manual June 30, 2008
Figure 3-20: MUX States
PREMUX State
Once the GRLC logical communication channel between the DTE and G24 has been established,
the RS232 cable is connected and the DTE device is ready to communicate.
MUX-Init State
This is an in-between state during which the G24 and DTE move from PREMUX to MUX.
Note: In this state there are no G24 indications or AT commands such as RING indicator (RI),
and so on.
MUX State
In this state, the DTE and G24 communicate with the MUX 27.010 protocol stack over RS232.
Supported 27.010 Protocol Services
The following table lists the services defined in the 27.010 protocol that are supported by the
MUX feature.
MUX-Init
PREMUX
MUX
Power-up
AT+CMUX
Time-out
CLD
DTR toggle
(when AT&D4)
SABM0
CLD or DISC0
(When only DLC0 is opened)
DTR toggle when AT&D is 4
Service Description
Start Up Used to start the multiplexer operation over the serial channel.
DLC
Establishment
Services
Used to open virtual multiplexer channels.
Data Services