Determining How Many Terminators You Need - Allen-Bradley ControlNet 1786-6.2.1 Planning And Installation Manual

2-6 Planning A ControlNet Cable System
Determining How Many
Terminators You Need
Publication 1786-6.2.1 - April 1988
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maximum allowable segment length of high-flex cable =
(20.29 db - number of taps in segment * .32 db)
cable attenuation @ 10MHz per 304 m (1000 ft)
Note: Cable attenuation is defined as the signal loss measured at 10 MHz per
1000 ft (304 m) of cable. Cable attenuation for ControlNet cables are
listed in publication AG-2.2, ControlNet Cable Systmems Component
List.
Example
If your segment requires 3 taps using 1786-RG6F/B cable, the maximum segment length is:
([20.29 db - 3*.32 db] / 7.18 db] * 1000)
(19.33 db / 7.18 db) * 1000 = 820 m (2692 ft)
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