Specifications

X723-3001514-3Issue 2
4.3 Dual LIU Patchfield
The patchfield on the Dual LIU is divided into two halves. Each half
provides the communication of management data between the TS0 non-
frame word of one of the PCM lines and the 'M' bus. Each half of the
patchfield may have one of seven pre-programmed patchfields
independently selected for each management configuration.
Table 4-2 shows the patchfields that have been pre-programmed into the
dual LIU management firmware DT995D. The electrical equivalent
diagrams can be found in Appendix A. If access to the Remote Alarm bit 3
is required within the patchfield, the Dual LIU must be fitted with
patchfield DT995E. Contact Case Communications for details of this patchfield.
Line 1 on the Dual LIU uses management bus lines M1 & M2 for
communication with the system controller or other LIUs. Line 2 uses
management bus lines M3 & M4. In the non-frame word of TS0, bits 4 &
5 are used for branch A poll and response respectively, bits 6 and 7 are
used for branch B. Patchfield 1 should be selected for unused PCM lines.
4.3.1 Cross-connect Bits
On the Dual LIU it may be necessary for polls and responses on one PCM
line to be transferred to the other PCM line as well as being routed to the
management bus. To enable this to happen the patchfields have internal
registers which are used to store data from one half of the patchfield so
that it can be input to the other half. In this way 2 bits of data can be
transferred from one PCM line to the other in each direction. These
signals are termed X1, X2 for line 1 and X3, X4 for line 2.