发表于:2006-02-09 14:02:00
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A.1 AI801 Analog Input Module, 0...20 mA
A.1.0.1 Features
• 8 channels for 0...20 mA,
4...20 mA d.c., single ended
unipolar inputs
• 1 group of 8 channels isolated
from ground
• 12 Bit resolution
• Input shunt resistors protected
to 30 V by PTC resistor
• Analog inputs are short circuit
secured to ZP or +24 V
• EMC protection
• DIN rail mounting
• The input is HART
compatible.
• Process and power
connections via detachable
connectors
A.1.0.2 Description
The AI801 Analog Input Module has 8 channels for current input.
The current input is able to handle a short circuit to the transmitter supply at least 30
V d.c without damage. Current limiting is performed with a PTC resistor. The input
resistance of the current input is 250 ohm, PTC included.
The EMC protection is placed on the module.
The module distributes the external transmitter supply to each channel. This adds a
simple connection to distribute the supply to 2-wire transmitters. There are no
current limiting on the transmitter power terminals. All eight channels are isolated
from the ModuleBus in one group. Power to the input stages is converted from the
external 24 V.
One STATUS LED indicates module status. The STATUS LED can be Green, off or
Red. The STATUS LED Green indicates normal operation. The STATUS LED Red
indicates that the module is in Init state or Not configured state. In Not configured
state the STATUS LED is turned off after the first valid access to the module.
The reset circuitry gives a reset signal when the POWOK signal is active. The
POWOK comes from the FCI after power is applied.
A.1.0.3 Technical Data
Table A-1 AI801 Analog Input Module Specifications at 25°C
Feature
AI801
Analog Input Module
Number of channels 8
Type of input Unipolar single ended
Measurement range 0...20 mA, 4... 20 mA
Under/over range -0% / +15%
Input impedance (at current input)
(including PTC)
≥230 Ω, ≤270 Ω
Maximum field cable length 600 meters, (656 yd.)
Voltage input, maximum non-destructive 30 V d.c.
NMRR, 50 Hz, 60 Hz >40 dB
Intrinsic error (IEC51-1) Max. 0.1%
Resolution 12 bit
Temperature drift Typ. 50 ppm/°C
Max. 80 ppm/°C
Update cycle time 1 ms
Current consumption 24 V external 30 mA
Current consumption 5 V 70 mA
Power dissipation 1.1 W
Maximum ambient temperature 55/40° C
(131/104° F)(1)
Input filter cut off frequency
Second order filter
3.5Hz
Isolation Groupwise isolated from ground
(RIV=50 V )
Safety classification Class I according to IEC 536; (earth
protected)
Protection rating IP20 according to IEC 529, (IEC 144)
Rated insulation voltage 50 V
Dielectric test voltage 500 V a.c.
Width 86.1 mm (3.4”)
Depth 58.5 mm (2.3”)
Height 110 mm (4.33”)
Weight 0.24 kg (0.53 lbs.)