Multiplexer User's Guide

Confidential / Released

s

mobile

4.3.9 Modem status command (MSC)

The Modem Status Command is used for software flow control.

Command

 

Length

 

DLCI

 

 

V.24 signals

 

Break Signals

1 octet

 

1 octet

 

1 octet

 

 

1 octet

 

 

(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

 

 

 

 

 

 

 

 

 

 

1

 

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

Mux_guide_v06

Page 28 of 36

30.06.2004

Page 28
Image 28
Siemens Mux_guide_v06 manual Modem status command MSC