Azbil 700 series - Internal Block Diagram of the 700 Series

6-10
6-8 Internal Block Diagram of the 700 Series
1) Internal block diagram of the 700 Series
Output Signal
Converter
Communication
I/F
Photo
Isolater
Surge Absorber
250Ω
DC24V
Electrical Isolation
Microprocessor
Digital Processing
Communication I/F
Analog I/F
A/D
Converter
Input Signal
Converter
Power Supply
VTD
（Position
Sensor）
Pilot
Relay
Pressure
Sensor
Controller
Feedback
Lever
Control Valve
Surge Absorber
DC4‒20mA
IIN
Local User
Interface（LUI）
EPM
Driver
EPM
（Electrical-Air
Converter）
A/M
Switch
OUT
Air Supply
140‒700kPa
SUP
AVP702
AVP701
DC4‒20mA
Figure 6-4
Figure 6-5
EPM
Drive Signal (%)
EPM drive signal
PID
control
operation
Flow amount
characteristic
signal
conversion
INPUT
% IIN
Input
signal
ranging
Input
current
caribration
INPUT
mA
Input signal
DC4–20mA
DC4–20mA
Output signal
Travel
transmission
Travel (%)
VTD
Focibly flly
opening/closing
signal
conversion
Set Point (%)
−
Positioner
forward/
reverse
Air signal
amplification
Actuator
forward/
reverse
Valve plug
forward/
reverse
Zero span
ranging
Reverse
input
characterization
Fail safe
processing
Output
current
calibration
Pilot relay
Actuator
Valve
Valve
opening
detection
Travel
Transmission (%)
Position (%)