SMAR FI303, Руководство по эксплуатации, техническому обслуживанию и инструкциям

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FI303 - Operation and Maintenance Instruction Manual
1.4
Bus topology (See Figure 1.5 – Bus Topology) and tree topology (See Figure 1.6 – Tree Topology)
are supported. Both types have a trunk cable with two terminations. The devices are connected to
the trunk via spurs. The spurs may be integrated in the device giving zero spur length. A spur may
connect more than one device, depending on the length. Active couplers may be used to extend
spur length.
The total cable length, including spurs, between any two devices in the Fieldbus should not exceed
1900m.
The connection of couplers should be kept less than 15 per 250m. In following figures the
DP/PA link depends on the application needs.
Spur
Terminator
Spur
Spur
Shield
Junction
Box
+ +
+
Analog
Ground
+
-
+
-
Figure 1.5 - Bus Topology
Analog
Ground
+
-
+
-
Coupler
+
+
+
+
Terminator
Enabled
Junction
Box
Figure 1.6 - Tree Topology