Specifications

4 Message Reference
42
4.3.6 MVD_MSG_SC_LISTEN - CT bus Listen Request
Synopsis
Message sent to the DSI SPCI Board to establish a connection from the CT bus to an
outgoing timeslot on an T1/E1 Line Interface Unit (LIU).
Format
MESSAGE HEADER
Field Name
Meaning
type
MVD_MSG_SC_LISTEN (0x7e17)
id
0
src
Sending Module ID
dst
MVD_TASK_ID (0x10)
rsp_req
Used to request a confirmation
hclass
0
status
Status Response (if confirmation requested)
err_info
0
len
6
PARAMETER AREA
Offset
Size
Name
0
2
liu_id
2
2
timeslot
4
2
sc_channel
Description
This message is sent to the DSI SPCI Board to establish a connection from the CT bus
to an outgoing timeslot on the T1/E1 Line Interface Unit (LIU). It is issued by the
application and is typically used at the start of each call although it may also be issued
during a call to connect to a different resource.
Correct operation of this message is dependent upon the use, at initialization time, of
the MVD_MSG_SC_DRIVE_LIU message (or the LIU_SC_DRIVE command in config.txt
when using s7_mgt).
When a new call arrives the application uses this message to connect the appropriate
resource from the CT bus out to the network. When the call finishes, the application
uses the MVD_MSG_SC_FIXDATA message to generate the appropriate IDLE pattern
on the LIU.
The MVD_MSG_SC_LISTEN message can also be generated at configuration time using
s7_mgt as a result of the SCBUS_LISTEN command in the config.txt file. However, this
only sets up a static configuration and still requires the user application to control any
dynamic connections.