II - DCE FEL ČVUT v Praze

SIMATIC S7 Ex Analog Modules
Interference rejection, error limits
Interference voltage rejection for f = n x (f1 1 %),
(f1 = interference frequency)
Common-mode rejection
(UISO < 60 V)
> 130 dB
Normal-mode rejection
(interference peak value
< rated value of input
range)
> 40 dB
Crosstalk attenuation between
inputs (UISO < 60 V)
> 70 dB
Operational limit (in total temperature range, referred to
input range)
25 mV
0.09 %
50 mV
0.06 %
80 mV
0.05 %
250mV/500mV/1V 0.04 %
Basic error (operational limit at 25C, referred to input
range)
25 mV
0.018 %
50 mV
0.014 %
80 mV
0.011 %
250mV/500mV/1V 0.008 %
Temperature error (referred to input range)
25 mV
0.0019 %/K
50 mV
0.0013 %/K
80 mV
0.0011 %/K
250mV/500mV/1V 0.0010 %/K
Linearity error
(referred to input range)
0.003 %
Repeatability (in steady-state
condition at 25C,
referred to input range)
3-60
0.003 %
Interference rejection, error limits continued
The accuracy of temperature
measurement with external
compensation with thermal
resistors is derived from:
The accuracy of temperature
measurement with external
compensation with
compensation box is derived
from:
The accuracy of temperature
measurement with
compensation of the external
reference junction maintained
at 0C / 50C is derived from:
The accuracy of temperature
measurement with internal
compensation (terminal
temperature) is derived from:
– Error for analog
input of the type of
thermocouple used
– Accuracy 1) of the
type of thermal
resistor used for
compensation
– Error 1) of
compensation input
– Error for analog
input of the type of
thermocouple used
– Accuracy 1) of
compensation box
– Error 1) of
compensation input
– Error for analog
input of the type of
thermocouple used
– Accuracy 1) of
reference junction
temperature
– Error for analog
input of the type of
thermocouple used
– Accuracy 1) of
internal reference
junction
temperature 0.5 K
1) Due to the constant increase in the thermocouple characteristic at higher temperatures, the error in the compensation
element is less effective than at temperatures in the vicinity of the compensation temperature. Exception: Thermocouple
types J and E (relative linear progression)
Due to the little increase in the range from approx. 0C to 40C, the lack of compensation of the reference junction
temperature has only a negligible effect in the case of thermocouple type B. If there is no compensation and the
measurement mode ”Compensation to 0C ” is set, the deviation in thermocouple type B during temperature
measurement is between 700C and 1820C < 0.5C
500C and 700C < 0.7C.
”Internal compensation” should be set if the reference junction temperature closely corresponds to the module
temperature. As a result, the error for the temperature range from 700 to 1820C is reduced to < 0.5C.
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04