Appendix B: MUX
This appendix contains the following sections:
•
PREMUX State, below
•
Mux-Init State, below
•
MUX State,
•
Software Procedures Related to RS232 HW Lines,
PREMUX State
Entry to State
•
When the G24 powers up.
Exit from state:
•
When the DTE sends the +CMUX command to the G24 to start the MUX stack and the G24
acknowledges with an OK response. (The MUX-Init state then begins.)
MUX-Init State
This state has two phases:
•
The 1st phase is the very short period when the G24 is getting ready to communicate with the
DTE over the MUX protocol.
•
The 2nd phase is when the G24 is ready and is waiting for the DTE to begin using the MUX
protocol by sending a special low-level byte sequence (SABM0 frame).
Entry to state:
•
When the G24 receives the +CMUX command and returns a success response (OK).
Exit from state:
•
If a timeout occurs due to the failure of the G24 to receive the SABM0 frame after a
predefined interval. The G24 then returns to the PREMUX state. The interval is defined to 10
seconds.
•
If the RS232 connection is closed, the G24 returns to the PREMUX state.
•
After a SABM0 frame is received, the G24 moves on to the MUX state.
December 31, 2007
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