ONICON F-2600 - Manual (Page 44)

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F-2600 & F-2700 Vortex Flow Meter Manual 02/15 - 0808-7 / 19204 Page 44
DC powered meters only
R
L
> 250 Ohm
DC Power
DC Common
mA Meter For HART
communications
the signal loop
must have a
minimum of 250
ohms load
resistance.
AC units only
Meter Provided DC
Power
R
L
> 250 Ohm
24 VDC
24 VDC
For HART
communications
the signal loop
must have a
minimum of 250
ohms load
resistance.
mA Meter
Figure 32. Non-Isolated 4–20 mA Output Using Meter Input Power Supply
Figure 33. Isolated 4–20 mA Output Using Meter Provided Power Supply
2.7.3 Frequency Output Connections
The frequency output is used for a remote counter. It can be scaled to output a 1 to 10 kHz
signal proportional to mass or volume flow, temperature, pressure or density.
The frequency output requires a separate 5 to 36 VDC power supply; however, there are
current and power specifications that must be observed. The output can conduct a current
up to 40 mA and can dissipate up to 200 mW. The output is isolated from the meter
electronics and power supply.
There are three connection options for the frequency output. The first has a separate power
supply (Figure 36). The second uses the flow meter power supply (Figure 37)
(DC powered units only), and the third uses the internal 24 VDC power supply (Figure 38)
(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 frequency output. Use the second configuration if
the voltage at the flow meter power supply is an acceptable driver voltage for the load
connected. (Take into account that the current used by the frequency load comes from the
meter’s power supply). Use the third configuration if you have an AC powered unit only.
In any case, the voltage of the frequency output is the same as the voltage supplied to the
circuit.