JTS CS-120 Series Manual page 17

For instance:
Originally, if the number of conference units is less than 90 without extension cable,
CS-120CU has 3 7P-DIN adaptors: every adaptor can connect with a maximum of 30
conference units with LCD, and a CU can connect with 90 conference units. However, if
the distance between conference units and CU is about 100 m, according the previous
table, every 7P-DIN adaptor can only connect with 16 conference units with LCD, and a
CU can only connect with 48 conference units.
Connect with CU
Connect with the next conference unit
12
CS-120 Conference System Product Manual
Connect buckle
CS-120DU
D7120-XX extension cord
CS-120DU
The number of
connectable
conference
units according
to the length of
extension cord
(Table 3-1)
Connect with the next
conference unit
or
Connect with terminal
connector if it is the last
conference unit
CS-120DU
CS-120CU