Flomec 490, Инструкция по эксплуатации, Страница: 11 / 20

Electrical connections 10
3.6 Quadrature outputs
Insertion Meters supplied with the QP option produce two NPN open collector pulse outputs
from two Hall Effect sensors. The outputs are
“ phase offset ” in their timing so that external
electronics are able to differentiate. These outputs may be used to assure output signal
integrity or to measure bi-directional flow.
3.7
Bi-directional flow
The Insertion Meter is capable of accurately measuring flow in both directions without
modification. Meters fitted with the QP output option (quadrature pulse output) may be
interfaced with the Pulse Discriminator Module (PD2). The PD2 accepts the Quadrature pulse
inputs & from these will discriminate between forward & reverse flow. Two individual &
proportional pulse outputs can then be sent to appropriate totalising registers or an add and
subtract flow rate totaliser.
It is important to note that the Quadrature Pulse option has the same pulse resolution
(pulses/unit volume) as a standard Insertion Meter for both forward & reverse outputs.
Flowmeter with QP outputs
PD2 Pulse Discriminator
5~24Vdc maximum
supply
(forward flow)
Output Signal 1
Ground
(reverse flow)
Output Signal 2
Reverse flow Sig
.
Forward flow Sig.
-0V
+8~24Vdc
1
2
5
4
Output signals
Sig.1
Sig.2
-0V
+Vdc
7
Reg
Reg
X
X
Vdc
+
+
-0V
9
6
10
Screen
Red ~ Vdc
b2
Black ~ -0V
White ~ output 1
Blue ~ output 2