Fisher-Rosemount HART 275, Product Manual

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1-3
NOTE: For the HART Communicator to function properly, a minimum of 250
ohms resistance must be present in the loop. The HART Communicator
does not measure loop current directly.
Figure 1-3 and Figure 1-4 illustrate typical wiring connections between the
HART Communicator and any compatible device.
FIGURE 1-3. Connecting to the Transmitter Comm Terminals.
FIGURE 1-4. Connecting the HART Communicator to the Loop.
R
L
≥
250
Ω
Power
Supply
+
_
+
_
_
+
mA +
_
+
_
Current
Meter
+
_
HART-compatible
Device
_
+
Power
Supply
_
+
+
_
Current
Meter
_
+
R
L
≥
250
Ω
_
+
_
+
Device
mA