Micro Motion Fisher Rosemount RFT9739, Инструкция по эксплуатации

Страница: 37 / 130

Output Wiring
continued
RFT9739 Rack-Mount Transmitter Instruction Manual
27
O
u
tp
ut Wi
ri
ng
Star
tu
p
T
ro
u
b
le
s
hoo
ting
Be
fo
re
Y
o
u
B
e
g
in
Getti
ng Sta
rted
M
oun
ting
P
o
w
e
r-
Suppl
y and
Sen
s
or Wi
ri
ng
5.3 Primary and secondary
mA outputs The RFT9739 primary and secondary mA output signals can be
independently configured, and can represent flow, density, temperature,
event 1 or event 2. With a pressure transmitter, the primary and
secondary mA output signals can also represent pressure. For
information on configuring mA outputs for events, see any of the
following manuals or AMS on-line help:
•
Using the HART Communicator with Micro Motion Transmitters
• Using ProLink Software with Micro Motion Transmitters
• Using Modbus Protocol with Micro Motion Transmitters
The mA outputs can produce a user-selected 0-20 or 4-20 mA current.
(See "Milliamp output scaling," page 9.)
• When configured to produce 4-20 mA current, the mA output loop can
supply loop-powered process indicators.
• For transmitters with software version 3.8 or higher, when
configured to produce 4-20 mA current, the mA outputs are compliant
with the NAMUR NE43 standard. (All RFT9739 transmitters shipped
after November 1999 have software version 3.8 or higher.)
In compliance with the NAMUR NE43 standard:
• 4-20 mA outputs will produce a live signal from 3.8 to 20.5 mA.
• 4-20 mA outputs will not produce a signal between 2.0 and 3.8 mA, or
between 20.5 and 22 mA.
• 4-20 mA output performance is illustrated in Figure 5-2.
Figure 5-2. 4-20 mA output performance
CAUTION
Milliamp output range has changed.
When configured for 4-20 mA, milliamp outputs will not
output live signals between 2.0 and 3.8 mA, or between
20.5 and 22 mA.
Systems that rely on milliamp output signals in the ranges
listed above might not perform as expected. For RFT9739
transmitters shipped after November 1999, outputs will
saturate at 3.8 and 20.5 mA, unlike previous versions of
these instruments.
Reconfigure systems as necessary.
2 3.8 22 20.5
Operating range (live signal)
Output, mA
Downscale
fault indication level Upscale
fault indication level