Azbil 700 series - Input Signals and Travel Transmission Power

2-17
Figure 2-20 Wiring when the Monitoring System Is a Voltage Input Device
• Use only one of the two ground terminals (internal or external) and perform the ground
work according to all local laws and ordinances governing electrical work.
2-3-4 InputSignalsandTravelTransmissionPower
1) Inputsignal
The input signals to this device are 4–20 mA DC. These input signals are also used as
the power source to drive the internal circuit.
Handling Precautions:
• Do not use any more than 24 mA DC.
• It will not operate properly with less than 3.85 mA DC.
Cautions
Do not apply the overvoltage to the terminals for the input signal. The overvoltage may
cause the failure of the device due to fire damage of the printed wiring boards.
2) TravelTransmissionPower
The travel transmission power is 17.9–45 V DC.
The load resistance of connections to the travel transmission loop should fall within the
operating range shown below for the power voltage to be used.
Handling Precautions:
Do not apply the travel transmission power than 45 V DC.
Figure 2-21 Supply Power Voltage/Load Resistance Features
Monitoring
system
(Voltage
250Ω min.
*
1
：
Refer to the gure 2-18
*
1
input)
525
247
17.9 24 450
1,484
(Ω)
Supply voltage E (V DC)
42
*2
1,347
R
E - 12.5
0.0219
R=
External load resistance
Operable range
Operating
range