Emerson Micro Motion Viscomaster Installation Manual page 26

Wiring
Figure 3-2:
mA1+
HART
mA2
RS-485
PWR
A. 24 VDC
B. R
load
C. HART-compatible host or controller; and/or signal device
D. Signal device
Note
For operating the milliamp outputs with a 24V supply, a maximum total loop resistance of 657
allowed.
CAUTION!
• To meet the EC Directive for Electromagnetic Compatibility (EMC), use a suitable
instrumentation cable to connect the meter. The instrumentation cable should have individual
screens, foil or braid over each twisted pair, and an overall screen to cover all cores. Where
permissible, connect the overall screen to earth at both ends (360° bonded at both ends).
Connect the inner individual screens at only the controller end.
• Use metal cable glands where the cables enter the meter amplifier box. Fit unused cable ports
with metal blanking plugs.
22
Wire power and outputs in a HART single-loop environment
A A
B
(250 Ω resistance)
A
B
A
B
Micro Motion Heavy Fuel Viscosity Meter
C
D
RS-485 A
RS-485 B
A
Ω is