RT318
1
8-channel RTD input
Type RT318
Category RTD ( Resistance Temperature Detector ) input
Resistance temperature
detectors
Pt100
Measuring method Three-wire system
Load current 1 mA
Temperature measurement
range
-50
°
to +270
°
C (-58
°
to +518
°
F)
Converted data 800 to 4000
Input channel 8 channels / module
Insulation Photo-coupler insulation (not isolated between the channels)
Conversion rate 400 ms / 8 channels
Resolution
12 bits / 0.025 % ( 0.1
°
C / count )
Wire resistance correction
range
Within 4
Ω
Overall accuracy ±
0.3
%
(at 25
°
C)
Tepaerature drift ±
100 ppm /
°
C
Internal current consumption 5 Vdc, 600 mA or less
Insulation resistance
10 M
Ω
(500 Vdc)
Withstand voltage 500 Vac, 1 minutes ( between internal and external circuits)
Weight 500 g
Internal circuit
Internal circuit
Buffer
memor
y
5 Vdc
+15V
-15V
0V
AMP
Input filter
1A
1B
1C
1G
PC : Photo-coupler
CH1
CH8
8A
8B
8C
8G
Multiplexer
DC/DC
AG
AG
Rref
Rref
ADC
PC
Current source
1 mA
1 mA
Wire break
detection
PC