II - DCE FEL ČVUT v Praze

SIMATIC S7 Ex Analog Modules
Temperature range
type B
3-20
Table 3-19 shows the representation of the digitized measured value for the
temperature range, sensor type B.
Table 3-19 Representation of the digitized measured value of an analog input
module (temperature range, type B)
Temperature
range in C
type B
Decimal Hexadecimal Range
> 2070.0 32767 7FFFH Overflow
2070.0
:
1820.1
1820.0
:
:
200.0 1)
:
0.0
-0.1
:
-150.0
20700
:
18201
18200
:
:
2000
:
0
-1
:
-1500
50DCH
:
4719H
4718H
:
:
7D0H
:
0H
FFFFH
:
FF24H
Overrange 2)
Rated range
Underrange 2)
< -150.0 -32768 8000H Underflow
In the case of incorrect wiring (e.g. polarity reversal, open inputs) or a sensor fault in
the negative range (e.g. incorrect type of thermocouple), on dropping below FA24H
the analog input module signals underflow and outputs 8000H.
1) The module linearizes the range from +1820 to -200C for type B. Below -200C,
the rise of the characteristic curve decreases to such an extent that, from this point,
precision evaluation is no longer possible. The rise in the characteristic curve at this
point is retained until underrange is reached.
The characteristic curve of the thermocouple does not feature monotone
characteristics in the temperature range between 0 and 40 C. Measured values
from this range are not distinctly allocated to a specific temperature.
2) The characteristic of the thermocouple is not defined in the overrange and
underrange. The rise of the characteristic curve is retained on leaving the linearized
range. It is not possible to specify the accuracy of these ranges.
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04