Specifications

4 Message Reference
70
Parameters
A description of the permitted parameter values are given below. When the board is
initially configured, all the LIUs are initialized to a disabled condition. The
LIU_MSG_CONFIG message includes the following parameters:
liu_type
The physical interface type. The preferred method for configuring an E1 interface is to
set a value of 5. The following table shows the permitted values and their meanings.
Value
Description
1
Disabled (used to deactivate a LIU). In this mode, the LIU does not produce an output
signal.
3
E1 120ohm balanced interface
4
T1 (including J1)
5
E1 120ohm balanced interface
line_code
The line coding technique. The following table shows the permitted values and their
meanings.
Value
Description
1
HDB3 (E1 only)
2
AMI with no Zero Code Suppression
3
AMI with Zero Code Suppression
The appropriate bit in the clear_mask parameter may be set to disable Zero Code
Suppression for individual timeslots if required (T1/J1).
4
B8ZS (T1/J1)
frame_format
The frame format. The following table shows the permitted values and their meanings.
Value
Description
1
E1 double frame (E1 only)
2
E1 multiframe (E1 only)
4
D3/D4 (Yellow alarm = bit 2 in each channel; T1 only)
7
ESF (Yellow alarm in data link channel); T1 only)
9
J1 frame format. (liu_type must be 4; T1)
10
Unstructured (HSL)