User manual

32
Section 2 MC-III™ EXP Flow Analyzer
Flowmeter Frequency Output
The owmeter frequency (amp & square) output provides an open drain transistor output at the turbine meter
frequency, which may be used to provide ow rate and/or total information to peripheral equipment. The
output requires a two-conductor cable from the MC-III EXP to the remote frequency readout device requiring
50 mA or less and a 5 to 30 VDC power supply (Figure 2.15).
Caution: The owmeter frequency output and 4-20 mA rate output are not isolated from each other
and cannot be used simultaneously.
Caution: When using the owmeter 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.
TB1
PULSE
INPUT
RESET
INPUT
TFM
A&S
GND
T
B
3
EXT POWER
TB2
RS485
SLAVE
4-20
OUT
PULSE
OUT
6
-
3
0
V
D
C
J1
J2
RESET
SWITCH
BATTERY
Leave this
end of shield
disconnected.
POWER SUPPLY
5 to 30 VDC
FREQUENCY
READOUT DEVICE
*
Resistor may be included in frequency
readout device. Size the resistor to limit
the current to 50 mA.
4-20 mA and flowmeter frequency
(amp & square) cannot be used
simultaneously.
*
TB3 MARKINGS:
GND = SIGNAL GROUND
A&S = AMP & SQUARE
Figure 2.15—Flowmeter frequency (amp & square) output wiring