Sierra INNOVA-MASS 240-VT, Инструкция по эксплуатации, Страница: 45 / 146

Chapter 2 Installation Sierra 240/241Series Instruction Manual
2-30 IM-240
AC or DC powered meters
Freq. Out +
Freq. Out -
Freq. Out voltage = +V
Select resistor so that current
through Freq. Out <= 40 mA
Figure 2-32. Isolated Frequency Output Using External Power Supply
PWR
PWR
DC Powered meters only
Freq. Out voltage =
Freq. Out +
Freq. Out -
Figure 2-33. Non-Isolated Frequency Output Using Input Power Supply
+
24 VDC Out
- 24 VDC Out
AC units only
Meter provided DC Power
Freq. Out +
Freq. Out -
Freq. Out voltage =
Figure 2-34. Isolated Frequency Output Using Meter Provided Power Supply
Pulse Output Connections
The pulse output is used for a remote counter. When the preset volume or
mass (defined in the totalizer settings, see page 3-10) has passed the me-
ter, the output provides a 50 millisecond square pulse.
The pulse output optical relay is a normally-open single-pole relay. The
relay has a nominal 200 volt/160 ohm rating. This means that it has a
nominal on-resistance of 160 ohms, and the largest voltage that it can
withstand across the output terminals is 200 volts. However, there are cur-
rent and power specifications that must be observed. The relay can con-
duct a current up to 40 mA and can dissipate up to 320 mW. The relay
output is isolated from the meter electronics and power supply.
There are three connection options for the pulse output
–
the first with a sepa-
rate power supply (Figure 2-30), the second using the flow meter power
supply (Figure 2-31)(DC powered units only), and the third using the inter-
nal 24 VDC power supply (Figure 2-32)(AC powered units only). Use the
first option with a separate power supply (5 to 36 VDC) if a specific voltage
is needed for the pulse output. Use the second configuration if the voltage at