AW T 210
H A R T 2- W I R E T R A N SM I T T ER | CO M/AW T 2 10/H A R T- EN R E V. B
7
HART point-to-point analog signal and power wiring (loop current mode enabled)
Make connections to the HART communication module as
shown in Figure 2.
Do not connect secondary communication device directly
across the power supply.
Figure 2 Analog mode wiring diagram
The signal wiring supplies all power to the transmitter.
The power supply limits are 14.0 to 42.0 V DC
(14 to 30 V DC for agency certified installation).
The minimum supply voltage is determined by the loop
resistance (R) as follows:
• minimum supply = 14.0 (volt) + 0.022 (amps) x R (ohms)
Load resistance must include any meters external to the
AWT210 transmitter, the wiring and the system input.
IMPORTANT (NOTE)
The equation for minimum supply voltage is based on
a maximum output current of 20 mA. In some cases
such as fail high or process variable over range
condition, the output current limits to 21.5 mA. To
support these cases, use 0.0215 instead of 0.020.
A secondary communication device can be connected anywhere
there is access to the signal wires as long as it is not connected
directly across the power supply.
IMPORTANT (NOTE)
Only one secondary device can communicate on the
loop at any given time.
+
+
+
–
–
–
+–
System power
supply
High impedance
controller,
recorder
or control
system
HART compatible
hand-held terminal
(secondary
communication device)
250
W