Siemens Mux_guide_v06 사용자 설명서

다운로드
페이지 36
Multiplexer User's Guide 
Confidential / Released 
s
 
m
o
 
b
 
i
 
l
 
e
 
Mux_guide_v06 
Page 28 of 36 
30.06.2004 
4.3.9  Modem status command (MSC) 
The Modem Status Command is used for software flow control.  
 
Comman
 
1 octet 
Length 
 
1 octet 
DLCI 
 
1 octet 
V.24 signals 
 
1 octet 
Break Signals 
(optional) 
1 octet 
 
Command:  
Bit 1 
Bit 2 
Bit 3 
Bit 4 
Bit 5 
Bit 6 
Bit 7 
Bit 8 
1 C/R 
0 0 0 1 1 1 
Figure 11: Modem status command (MSC) 
C/R bit:  Indicates whether the sequence is a command or a response. 
 
Length: 
Length = 2 , EA-Bit = 1 
 
 
DLCI:  
Bit 1 
Bit 2 
Bit 3 
Bit 4 
Bit 5 
Bit 6 
Bit 7 
Bit 8 
1 1 
DLCI 
 
 
V.24 signals:  
Bit 1 
Bit 2 
Bit 3 
Bit 4 
Bit 5 
Bit 6 
Bit 7 
Bit 8 
FC  RTC RTR reserved 
0 reserved 
0 RING DCD 
 
FC bit:   Flow control, included in all multiplexer versions 
FC = 1:  no frames are accepted 
 
The following bits for V24 status lines as described in this chapter are included in multiplexer 
protocol version 3 only. However, if you wish to use the advantages of this version it is 
absolutely necessary to switch on the version 3, otherwise version 1 will be used, see 
Chapter 5.2. 
 
Direction host application" module (for request only) MUX V3: 
RTC:   mapped to DTR 
 
RTR:   mapped to RTS  
Bit 5, 6, 7, 8 are not valid. 
 
Direction module 
" host application (for request only) MUX V3: 
RTC:   mapped to DSR 
RTR:   mapped to CTS 
RING:  mapped to RING 
DCD:   mapped to DCD 
Bit 5, 6 are not valid