Emerson Rosemount 1066 Quick Start Manual page 18

Quick Start Guide
Figure 2-1: Rosemount 1066 System Block Diagram
A. 4-20 mA and HART signal
B. Control system
C. Computer
D. Bridge
E. Field Communicator
2.3.1 HART
®
Refer to
the transmitter terminals. The power supply must be able to cover
the voltage drop on the cable as well as the load resistor (250 Ω
minimum) required for HART communication. The maximum power
supply voltage is 42.0 Vdc. For intrinsically safe installations, the
maximum power supply voltage is 30.0 Vdc.
Figure 2-2
line is the power supply voltage needed to provide 12.7 Vdc at the
transmitter terminals for a 22 mA current. The power supply must
provide a surge current during the first 80 milliseconds of start-up.
The maximum current is about 24 mA.
For digital communication, the load must be at least 250 ohms. To
supply the 12.7 Vdc lift off voltage at the transmitter, the power
supply voltage must be at least 17.5 Vdc.
18
power supply and load requirements
Figure 2-2. The supply voltage must be at least 12.7 Vdc at
shows load and power supply requirements. The upper
February 2024
Emerson.com/Rosemount