II - DCE FEL ČVUT v Praze

DIN IEC 584
Temperature range
type T
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04
The basic thermal e.m.f. values specified in the following comply with
DIN IEC 584.
Table 3-10 shows the representation of the digitized measured value for the
temperature range, sensor type T.
Table 3-10 Representation of the digitized measured value of an analog input
module (temperature range, type T)
Temperature
range in C
SIMATIC S7 Ex Analog Modules
Decimal Hexadecimal Range
> 540.0 32767 7FFFH Overflow
540.0
5400 1518H
:
:
:
Overrange
400.1
4001 0FA1H
2)
400.0
:
:
-230.0 1)
4000 0FA0H
:
:
:
-2300
:
F704H
Rated range
:
:
:
-270.0
-2700 F574H
-270.1 -2701 F573H Underrange 2)
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 F0C4H
the analog input module signals underflow and outputs 8000H.
1) The module linearizes the range from +400 to -230C for type T. Below -230C, 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.
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.
3-11