Dynasonics TFX Ultra Transit Time Flow Meters - Manual (Page 29)

90-265 VAC
AC Neutral
Control 1
Control 2
Frequency Out
4-20 mA Out
Reset Total
Signal Gnd.
Meter Power
Loop
Resistance
Signal Ground
7 VDC
Drop
Figure 24: 4-20 mA output
The 4-20 mA output signal is available between the 4-20 mA Out and Signal Gnd terminals as shown in Figure 24 .
Control Outputs [Flow Only Version]
Two independent open collector transistor outputs are included with the flow only model. Each output can be configured for
one of the following four functions:
Rate Alarm
Signal Strength Alarm
Totalizing/Totalizing Pulse
Errors
None
1 2 3 4 O
N
Figure 25: Switch settings
Both control outputs are rated for a maximum of 100 mA and 10…28V DC. A pullup resistor can be added externally or an
internal 10k Ohm pullup resistor can be selected using DIP switches on the power supply board.
Switch S1 S2 S3 S4
On
Control 1 Pullup
Resistor IN circuit Control 2 Pullup
Resistor IN circuit Frequency output Pullup
Resistor IN circuit
Square Wave Output
Off
Control 1 Pullup
Resistor OUT of circuit Control 2 Pullup
Resistor OUT of circuit Frequency Output Pullup
Resistor OUT of circuit
Simulated Turbine
Output
Table 4: Dip switch functions
OTE:
N
All control outputs are disabled when USB cable is connected.
For the Rate Alarm and Signal Strength Alarm the on/off values are set using either the keypad or the software utility.
Typical control connections are illustrated in
Figure 26 . Please note that only the Control 1 output is shown. Control 2 is
identical except the pullup resistor is governed by SW2.
SW1/SW2 90-265 VAC
AC Neutral
Signal Gnd.
Control 2
Frequency Out
4-20 mA Out
Reset Total
10k
VCC
1 2 3 4 O
N
Control 1
SW1/SW2 90-265 VAC
AC Neutral
Signal Gnd.
Control 2
Frequency Out
4-20 mA Out
Reset Total
Control 1
1 2 3 4 O
N 10…28
VDC
100 mA Maximum
Figure 26: Typical control connections
INPUTS/OUTPUTS
Page 29 March 2014