3
2
1
4
3
2
1
4
Terminal Block
Terminal Block
SIG
SIG
600
Ω
Max.
600
Ω
Max.
0V
0V
G
G
24VDC
24VDC
V
3
2
1
4
Terminal Block
12〜45VDC
Power
Analog
Indicator
In case of
curent input
＋
−
＋
−
3
2
1
4
Terminal Block
1ms(std.) or 50 ms
7V min.
1V max.
SIG
0V
V
12〜24VDC
Regulated
Voltage
1kΩ
10kΩmin.
3
2
1
4
Terminal Block
Totalizer
Analog Indicator
Load Resistor
G
※
＋
−
＋
−
＋
−
Power Supply
Capacity 60mA min.
B-144-12-E
14
8.3 Method of Connection
8.4 About Load Resistance Range
In the specification of two-wire transmission
system for analog and pulse signals, the power
lines also serve as signal lines.
The transmission loop requires a DC power
supply. If it is desired to connect an instrument in
a loop, the load resistance of both the instrument
and conductors must fall within the operating
range as shown in the graph at right.
Stsndard: Power supply voltage = 24VDC
Load resistance = 250
Ω
0
0
300
（600）
1650
12
（24）
45
Load Resistance
(Ω
)
Supply Voltage(V DC)
Operating
Range
3
2
1
4
Terminal Block
SIG
Max.50mA
1ms(std.) or 50 ms
0V
V
VDC
12〜24
E(≦30VDC)
R
Select R such that the
max. allowable current
is held below 50mA.
(1) Current Pulse Output
(2-wire system)
(2) Analog Output
(2-wire system)
(3) Open Collector Output
(3-wire system)
(4) Voltage Pulse Output
(3-wire system)
(5) Current Pulse + Analog Output
(4-wire system)
NOTE: OVAL circuit to accept current pulses comes in two
configurations as shown above. Refer to the receiving
instrument instruction manual before making connections.
NOTE: In case of voltage input, couple an external load
resistor (see the acceptable load resistance
range in Section 8.4).
NOTE 1: In OVAL receiving instruments, signal conversion
takes place with an internal load resistor. If you
build a system like the one shown here with a
commercially available totalizer of other make,
verify that the signal levels to the totalizer match,
since signal conversion from current pulses into
voltage pulses takes place according to the law
4/20mA
×
load resistance.
NOTE 2: If you use an OVAL receiving instrument in the
configuration shown here, make sure of the current
carrying capacity of receiving instrument's power
suply. lf it has problem in current carring capacity, a
separate power supply should be provided for the
analog Indicator.
※
Select the voltage input for the totalizer.
Make sure of the trigger level of voltage input and determine the
supply voltage and load resistance value.
