Tiway I Network Characteristics; Number Of Local Line Secondaries Vs. Cable Distance - Siemens SIMATIC TI500 User Manual

TIWAY I Network
Characteristics
TIWAY I Gateway User Manual
The TIWAY I network cable consists of a main cable or spine with droplines
or taps for each secondary. The maximum main line cable length, cable type,
tap length, tap spacing, number of secondaries, and maximum baud rates
are interrelated network variables and have a direct influence upon
network performance.
Figure 2-2 shows the relationship of cable distance to the number of
secondaries for different baud rates for two types of twisted-pair cable. The
cable distance (in thousands of feet) is shown vertically; the maximum
number of units that may be attached is shown horizontally.
30
19.2 kbps
25
38.4 kbps
20
57.6 kbps
15
115.2 kbps
10
8
7
6
5
4
115.2 kbps or lower
3
2
1
5
Cable Unit Loading (Number of Stations)
Figure 2-2 Number of Local Line Secondaries vs. Cable Distance
As shown in Figure 2-2, when you use Belden 9860 cable (or its equivalent),
up to 75 stations can be attached to a network operating at 38.4 kbps and
having a spine length of 20,000 feet. At 115.2 kbps, the maximum length of
a Local Line network having 248 stations is 10,000 feet.
10 20 50
Network Installation
Belden 9860
Belden 9271
100 250
I000000
2-5