Fisher 00275-8026-0001 manual 1-3

1-3
NOTE:For the HART Communicator to function properly, a minimum of 250
ohmsresistance must be present in the loop. The HART Com municator
doesnot measure loop current direct ly.
Figure 1-3 and Figure 1-4illustrate typical wiring connections between the
HARTCommunicator and any compatible device.
FIGURE1-3. Conne cting to the Transmitter Comm Terminals.
FIGURE1-4. Co nnecting the HART Communicator to the Loop.
RL≥250Ω
Power
Supply
+
_
+
_
_
+
mA+_
+
_
Current
Meter
+_
HART-compatible
Device
_+
Power
Supply
_
+
+
_
Current
Meter
_
+
RL≥250Ω
_+
_
+
Device
mA