Wiring the Analog outputs
Figure 4-1:
mA1+
HART
RS-485
PWR
mA2
A
A
B
RS-485 A
RS-485 B
C
D
B
B
A
A
A
A. 24 VDC
B. R
load
(250 Ω
resistance)
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
Ω
is
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.
Wiring
Installation Manual
23
