CTI 2500-RIO-B Installation and Operation Guide V1.4
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Belden 9271, which is smaller and more flexible, is suitable for use as drop lines as well as short
trunk lines. For trunk lines, this cable may be intermixed with Belden 9860.
Belden 9860 cable, which provides low attenuation and distortion, should be used for long trunk
lines.
NOTE: If the trunk line is Belden 9182, then the droplines must also be Belden 9182. If the trunk
line is Belden 3105A, 9860, or 9271, then the droplines can be 3105A, 9271, or 9182.
If you use cable types other than these, you should ensure the following requirement are met:
Characteristic impedance between 100 and 150 ohms (124 ohms optimum) High uniform twist
and spacing of conductors (twinaxial cable) Shield coverage approaching 100% DC resistance
smaller than the characteristic impedance Jacket suitable for the installation
Cable Lengths
Maximum permissible cable length is dependent on cable characteristics and number of terminal
blocks used in the installation. Terminal blocks are used to connect drop lines and/or extend Remote
I/O cable trunk line. The following table contains the maximum recommended cable length (Trunk
Drop Lines) for Belden® 3105A cable. It is possible to have longer cable runs if larger
diameter wire is used.
Number of Installed
Drop Lines
Maximum Cable Length in
Feet (Meters)
Belden 3105A
2-5
2200 (670)
6
2133 (650)
7
2067 (630)
8
2000 (610)
9
1933 (589)
10
1867 (569)
11
1800 (548)
12
1733 (528)
13
1667 (508)
14
1600 (488)
15
1533 (467)
16
1467 (447)
17
1400 (427)
