Emerson Rosemount 2051 Reference Manual page 74

Electrical Installation
February 2024
Figure 4-6: Load Limitation
• Maximum loop resistance = 43.5 × (power supply voltage – 10.5)
• The communication device 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
4.5.3 Wire the transmitter
NOTICE
Incorrect wiring can damage the circuit.
Do not connect the power signal wiring to the test terminals.
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, Emerson recommends unpaired three conductors or two twisted pairs.
74
(output code M)
®
load should be 100 kΩ or greater.
out
Reference Manual
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Rosemount 2051