Emerson Rosemount 2051 Reference Manual page 72

Electrical Installation
September 2020
Transmitter, the power supply used, and circuitry common to the transmitters, should not
have more that 20 Ω of impedance at 1200 Hz.
Figure 4-5: Load Limitation
• Maximum loop resistance = 43.5 × (power supply voltage – 10.5)
• The Field Communicator requires a minimum loop resistance of 250 Ω for
communication.
The total resistance load is the sum of the resistance of the signal leads and the load
resistance of the controller, indicator, I.S. Barriers, and related pieces. If intrinsic safety
barriers are used, the resistance and voltage drop must be included.
1–5 Vdc low power HART
Low power transmitters operate on 9–28 Vdc. The DC power supply should provide power
with less than 2 percent ripple. The V
4.6.3 Wiring the transmitter
CAUTION
Do not connect the power signal wiring to the test terminals. Incorrect wiring can damage
test circuit.
Note
Use shielded twisted pairs to yield best results. To ensure proper communication, use 24
AWG or larger wire and do not exceed 5000 ft. (1500 m). For 1–5 V 500 ft. (150 m)
maximum are recommended. unpaired three conductor or two twisted pairs is
recommended.
72
®
(output code M)
load should be 100 kΩ or greater.
out
Rosemount 2051 Pressure Transmitter
Reference Manual
00809-0100-4107