Rockwell Automation 1786-RG6F INSTL.INSTR CONTROLNET H-FLEX - Manual (Page 4)

4 ControlNet Standard and High-flex Coax Cable
Publication 1786-IN009B-EN-P - November 2003
The following tables and examples are provided to help you determine the lengths of cable
you can use in your system.
About Cable Attenuation
See Table 1 for attenuation for RG-6 and RG-6F cables.
if you are using The total allowable length of a segment depends on the
standard RG-6 cable
(1786-RG6/A with
attenuation of 5.99
dB) number of taps in your segment (there is no minimum trunk-cable section length
requirement).
The maximum allowable total length of a segment is 1,000 m (3,280 ft) with two
taps connected. Each additional tap decreases the maximum length of the segment
by 16.3 m (53 ft). The maximum number of taps allowed on a segment is 48 with a
maximum length of 250 m (820 ft).
maximum allowable segment length =
1000 m (3280 ft) - [16.3 m (53.4 ft) x [number of taps - 2]]
any RG-6 or RG-6F
cable (1786-RG6F/A) number of taps in your segment and length of any RG-6 cable.
maximum allowable segment length =
(20.29 dB - total taps in segment X .32 dB) X 1000 ft (304 m)
cable attenuation
1
@ 10 MHz per 1000 ft (304 m)
a combination of RG-6
and RG-6F cable number of taps in your segment and length of any RG-6 cable.
(Attenuation 1786-R6F per 1000 ft @ 10 MHz/Attenuation 1786-RG6 per 1000 ft @
10MHz) * length of 1786RG6F = equivalent length in 1786-RG6 cable.
1 Cable attenuation is defined as the signal loss as measured at 10MHz per 1000 ft (304.8 m) of cable. See Table 1 for cable
attenuation for RG-6 and RG-6F cables.
Table 1 Attenuation for RG-6 and RG-6F cables
cable type attenuation at 10 MHz per 1000 ft (304 m)
1786-RG6/A 5.99 dB
1786-RG6F/A 13.5 dB