Cameron NUFLO MC-III, Руководство пользователя

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Section 2 MC-III™ Panel Mount Flow Analyzer
TB1
PU
LS
E
IN
PU
T
RE
SE
T
IN
PU
T
TF
M
A&S
GND
TB
3
EXT POWER
TB2
RS
485
SL
AV
E
4-2
0
OU
T
PU
LS
E
OU
T
6-3
0 V
DC
J1
J2
RESET
SWITCH
BA
TT
ER
Y
POWER SUPPLY
8 to 30 VDC
LOAD
Resistor may be
included in readout
device.
4-20 mA and
flowmeter frequency
(amp & square)
cannot be used
simultaneously.
*
*
1100
800
200
0
LO
A
D
R
ES
IS
TA
N
C
E
(O
H
M
S)
8 12 24 30
LOOP SUPPLY VOLTAGE (VDC)
OPERATING
REGION
Figure 2.8—4-20 mA rate output wiring
Flow Meter Frequency Output
The flow meter frequency (amp & square) output provides an open drain transistor output at the turbine meter
frequency, which may be used to provide flow rate and/or total information to peripheral equipment. The
output requires a two-conductor cable from the MC-III Panel Mount to the remote frequency readout device
requiring 50 mA or less and a 5 to 30 VDC power supply (
Figure 2.9, page 23
).
Caution: The flow meter frequency output and 4-20 mA rate output are not isolated from each
other and cannot be used simultaneously.
Caution: When using the flow meter frequency output and powering the device from an
external power supply, make sure both power supplies share a common negative (-)
terminal or are totally isolated from each other.
The flow meter frequency output terminals on the MC-III Panel Mount circuit assembly are labeled A & S to
represent “amp & square” output.