The Interface Solution Experts
11
HIM
Smart HART
Loop
Interface and Monitor
Figure 5.
Installing a HIM Into the Loop Using an External Power Source to Power a Transmitter
READY
INPUT
TRIP 2
TRIP 1
COM
0
ADDR
COMMON
NC (normally closed)
NO (normally open)
4-20mA
DCS
Sensor
Input
NO
NC
+
–
24Vdc
Power
Source
R
HART Multivariable
Field Instrument
(Temperature
Pressure, Level
and Flow)
Analog Output tied to
Any Process Variable
Event Recorder
HART Communicator
can be connected
anywhere on the loop
COM
+IN
–IN
24Vdc
Power
+
–
R must be > 250 and <1100 Ohms
1
2
3
4
5
6
7
8
9
0
.
—
➤
➤
➤
➤
➤
➤
➤
25.1
deg-c
80.1
20.3
50.7
(+) DC
GND
(-) DCC
