Toa EXES-6000, Operating And Troubleshooting

Page: 5 / 60

2. Concept of Speech Link
2-1. Manual Exchange
Fig.3 Manually Operated Exchange (8 lines/2 links)
Fig. 3 shows the simplest telephone system.
When an attendant connects between 2 stations
with a strap, speech path can be set up between
them. The strap represents a link, and the number
of links can be increased as the strap increases in
number. You may presume that the attendant
functions as switch in this system.
2-2. Crossbar System
Fig. 4 shows the crossbar method which corres-
ponds to space division method in the classifica-
tion of speech path. The space division method is
mentioned in the next section 2-3. This method,
however, has both the advantage and the dis-
advantage; the advantage is that all stations in a
system can participate in the conversation at the
same time, while the disadvantage is that an
increase in the number of stations will require
greater number of switches as is evidenced by an
example of the EXES-6000 system with 128
stations where the required number of switches
totals
128
2
– 128 = 16,256 pieces.
Fig.4 Crossbar System Exchange (8 lines/full links)
— 2 —