Detcon 6400-N4X - Manual (Page 37)

1600/6400-N4X
1600/6400-N4X- Instruction Manual Rev. 1.1 Page 33 of 38
shown in (Figure 38). Repeaters are used to eliminate the t-taps or stubs, which can cause communication
problems. The location and number of stubs will dictate where repeaters need to be installed. Four repeaters
are installed to eliminate the stubs.
Figure 38 Four repeater Data Bus
Notice there are 5 different data buses that make up the communications network. The first one consists of the
master located in the control room, device 09, repeater #1, device 01, device 02, repeater #2, device 03, and
device 05. Notice the termination resistors at the beginning and end of this bus section. The second bus starts
at repeater #2. It consists of the repeater and device 04. Since this is a new bus, it has terminating resistors at
each end. The third bus starts at repeater #1. It includes device 08, repeater #3, device 07, repeater #4, and
device 06. It also has its own resistors. The fourth bus starts at repeater #3 and consists of the repeater, device
0A, and the terminating resistors. The fifth bus starts at repeater #4 and consists of the repeater, device 0B,
and termination resistors. This configuration isolates all of the t-tap stubs. This configuration should function
properly as long as the wire type and proper distances are observed.
The following chart shows an approximation of wire length vs. data speed. Detcon operates its equipment at
19,200bps and lower.
Figure 39 Wire length vs. data speed
09
08
0a
Control Room
01 02
07 06
0b
04
05
03
Rt
Rt
Rt
Rt
Rt
Rt Rt
Rt
Rt
Rt
repeater #2
repeater #1
repeater #3 repeater #4
100 mbps
10 mbps
1 mbps
100 kbps
10 kbps
1 kbps
0 ft 10 ft 100 ft 1000 ft 5000 ft 10000 ft