34
Length of cables
2-ring connection (using DUs)
2-ring connection (using IUs)
CU-DU DU-DU
EXT-
DU
Number of DUs
connected
Maximum
number of
units
connected
Number
of EXTs
needed
Number of IUs
connected
Maximum
number of
units
connected
Number
of EXTs
needed
L1
L2
L3
10 m
1.5 m
10 m
1 to 25 × 2 units
(total 50
units)
0 units
1 to 16 × 2 units
(total 32
units)
0 units
26 to 50 × 2 units
(total 100
units)
4 units
17 to 40 × 2 units
(total 80
units)
4 units
50 m
1.5 m
10 m
1 to 23 × 2 units
(total 46
units)
0 units
1 to 15 × 2 units
(total 30
units)
0 units
24 to 50 × 2 units
(total 100
units)
4 units
16 to 38 × 2 units
(total 76
units)
4 units
100 m
1.5 m
10 m
1 to 20 × 2 units
(total 40
units)
0 units
1 to 13 × 2 units
(total 26
units)
0 units
21 to 50 × 2 units
(total 100
units)
4 units
14 to 38 × 2 units
(total 76
units)
4 units
10 m
2.0 m
10 m
1 to 25 × 2 units
(total 50
units)
0 units
1 to 16 × 2 units
(total 32
units)
0 units
26 to 50 × 2 units
(total 100
units)
4 units
17 to 40 × 2 units
(total 80
units)
4 units
50 m
2.0 m
10 m
1 to 23 × 2 units
(total 46
units)
0 units
1 to 15 × 2 units
(total 30
units)
0 units
24 to 50 × 2 units
(total 100
units)
4 units
16 to 38 × 2 units
(total 76
units)
4 units
100 m
2.0 m
10 m
1 to 20 × 2 units
(total 40
units)
0 units
1 to 12 × 2 units
(total 24
units)
0 units
21 to 50 × 2 units
(total 100
units)
4 units
13 to 38 × 2 units
(total 76
units)
4 units
10 m
5.0 m
10 m
1 to 24 × 2 units
(total 48
units)
0 units
1 to 16 × 2 units
(total 32
units)
0 units
25 to 50 × 2 units
(total 100
units)
4 units
17 to 39 × 2 units
(total 78
units)
4 units
50 m
5.0 m
10 m
1 to 22 × 2 units
(total 44
units)
0 units
1 to 14 × 2 units
(total 28
units)
0 units
23 to 50 × 2 units
(total 100
units)
4 units
15 to 37 × 2 units
(total 74
units)
4 units
100 m
5.0 m
10 m
1 to 19 × 2 units
(total 38
units)
0 units
1 to 12 × 2 units.
(total 24
units)
0 units
20 to 50 × 2 units
(total 100
units)
4 units
13 to 35 × 2 units
(total 70
units)
4 units
The values in the tables above are calculated based on the following assumptions.
• The number of DUs that can be connected is based on the assumption that the ATUC-M is used.
• The number of IUs that can be connected is based on the assumption that ATUC-M, TALK LED, FLOOR LED, 8-Ω speaker units, 32-Ω
impedance headphones, and GPO terminals with LED x 4 (7 mA each) are being used.
• Given that Cat5e or higher cables are used. (Shielded cables with conductor size of 24AWG or higher in diameter are recommended.)
• 1-port daisy-chain connection/1 ring connection: Given that one of the DU CHAIN A/B terminals is connected in a DU/IU daisy-chain
or that the A-B terminal is connected in a ring.
• 2-port daisy-chain connection: Given that the same number of DUs/IUs are daisy chained to the DU CHAIN A/B terminals.
• 4-port daisy-chain connection: Given that the same number of DUs/IUs are daisy chained to both the DU CHAIN A/B terminals and the
same number of DUs/IUs are daisy chained to the DU CHAIN C/D terminals.
• 2-ring connections: Given that one ring connection is used for the DU CHAIN A-B terminals and for the DU CHAIN C-D terminals.
