Siemens SIMATIC TI555 User Manual

4-13
Cabling and Wiring the System
TI545/TI555 System Manual
Three commercially available cables provide an acceptable level of I/O
communication in an industrial environment when used in accordance with
T able 4-2.
• Belden cable 9860 is a large conductor cable that provides a low
attenuation and distortion for long trunk lines.
• Belden cable 9271 is a smaller and more flexible cable suitable for short
trunk lines and all drop line cables.
• Belden cable 9182 provides an intermediate level of size, flexibility , and
useful length. The 9182 cable is also available in a version (89182)
rated for a higher level of fire resistance and low smoke producing
properties.
Alternate cables should have a specified characteristic impedance between
100 and 150 ohms; 124 ohms being optimum. Other considerations for
alternate cables include: a high uniform twist and spacing of conductors
(usually found in cables called “twinaxial”), shield coverage approaching
100%, DC resistance of the installed cable length smaller than the
characteristic impedance, and a jacket suitable for the installation.
Characteristics of the cables listed in T able 4-2 are provided in T able 4-3 as
a guide for selecting alternate cables.
T able 4-3 Cable Characteristics
Belden
Cable Type
Center
Conductor
Outside
Diameter
Impedance Capacitance Velocity
9860
16 AWG solid
13.8 ohm/km
1 1.18 mm 124 ohms 35.8 pf/m 0.78 c
9271
25 AWG 7x33
104.3ohm/km
6.15 mm 124 ohms 40 pf/m 0.66 c
9182
(89182)
22 AWG 19x34
46 ohm/km
8.89 mm 150 ohms 28.9 pf/m 0.78 c
Alternate Cables

Siemens SIMATIC TI555 Specifications

General

Brand	Siemens
Model	SIMATIC TI555
Category	Controller
Language	English