Siemens Simatic S7-400 User Manual
Page 341
Analog Modules
5-125
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Technical Specifications of the SM 431; AI 8
RTD
16 Bit
Dimensions and Weight
Dimensions W
H
D
(in millimeters)
25
290
210
Weight
Approx. 650 g
Data for Specific Module
Number of inputs
•
For resistance-type sensor
8
4
Length of cable
•
Shielded
Max. 200 m
Voltages, Currents, Potentials
Constant current for
resistance-type sensor
Max. 1 mA
Isolation
•
Between channels and
backplane bus
Yes
Permitted potential difference
•
Between M
ANA
and
M
internal
(U
ISO
)
120 VAC
Insulation tested with
1500 VAC
Current consumption
•
From the backplane bus
Max. 650 mA
Power dissipation of the
module
Typ. 3.3 W
Analog Value Generation
Measuring principle
Integrative
Integration/conversion time/
resolution (per channel)
•
Parameterizable
(Does not go into the
response time)
Yes
•
Basic conversion time in
ms
22/25
•
Additional conversion time
for measuring resistance,
in ms
Max. 200
•
Resolution including sign
16/16 bit
•
Noise suppression
for interference frequency
f1 in Hz
60/50
Smoothing of the measured
values
Parameters can be
assigned in 4 stages
Basic response time of module
(all channels enabled)
22/25 ms
Suppression of interference, Limits of Error
Noise suppression for f = n
(f1
"
1%),
(f1 = interference frequency) n = 1, 2, etc.
•
Common-mode
interference (U
CM
< 120V)
•
Series-mode interference
(peak value of interference
< rated value of the input
range)
> 100 dB
> 50 dB
Crosstalk between the inputs
> 70 dB
Operational limit (over entire temperature range, referred
to 0 to 60
_
C input range)
•
RTD input
"
1.0
°
C
Basic error (operational limit at 25
°
C, referred to input
range)
•
RTD input
"
0.5
°
C
Temperature error (with
reference to the input range)
"
0.007%/K
Linearity error (with reference
to the input range)
"
0.2
°
C
Repeat accuracy (in the steady
state at 25
°
C, referred to the
input range)
"
0.2
°
C
Status, Interrupts, Diagnostics
Interrupts
•
Hardware interrupt when
limit has been exceeded
Parameters can be
assigned
•
Diagnostic Interrupt
Parameters can be
assigned
Diagnostic functions
Parameters can be
assigned
•
Group error display
–
For internal fault
–
For external fault
Red LED (INTF)
Red LED (EXTF)
•
Diagnostic information can
be displayed
Possible
Data for Selecting a Sensor
Input range (rated values) input
resistance
•
Resistance thermometer
Pt 100, Pt 200, Pt 500,
Pt 1000, Ni 100,
Ni 1000
•
Maximum input voltage for
voltage input (destruction
limit)
35 V continuous;
75 V for max. 1 s
(duty factor 1:20)
Connection of the sensor
•
For measuring resistance
With three-conductor
terminal
Possible
With four-conductor
terminal
Possible
Characteristic linearization
•
For resistance
thermometer
Pt 100,0,00385 to DIN
IEC 751
Ni 100, 0,00618 to DIN
43760
Unit for temperature
measurement
Degrees Celsius;
degrees Fahrenheit