Technical data of CPU 31xC   
6.6 Technical data of the integrated I/O 
  CPU 31xC and CPU 31x, Technical Data 
6-50  Manual, 01/2006 Edition, A5E00105475-06 
Technical data 
Interference suppression, error limits 
Interference voltage suppression for f = nx (f1 ± 1 %), (f1 = interference 
frequency), n = 1, 2 
 
•  Commonmode interference (U
CM
 < 1.0 V) 
> 40 dB 
•  Feedback interference (peak value of the interference < rated value of 
the input range) 
> 30 dB 
Crosstalk between the inputs  > 60 dB 
Operational error limits (across the temperature range, in relation to input 
range) 
 
•  Voltage/current 
< 1 % 
•  Resistance 
< 5 % 
Basic error limit (operational limit at 25 °C, in relation to input range)   
•  Voltage/current 
–  Linearity error during measurement of current and voltage 
(related to input range) 
< 0,7 % 
± 0,06 % 
•  Existence 
–  Linearity error during resistance measurement 
(related to input range) 
< 3 % 
± 0,2 % 
Temperature error (in relation to input range)  ± 0,006 %/K 
Repeat accuracy (in transient state at 25 °C, in relation to input range)  ± 0,06 % 
Status, interrupts, diagnostics 
Interrupts 
•  no interrupts when operated as standard 
I/O 
Diagnostics functions 
•  no diagnostics when operated as 
standard I/O 
•  For using technological functions, please 
refer to the 
Technological Functions
 
Manual. 
Encoder selection data 
Input ranges (rated value)/input resistance   
•  Voltage 
± 10 V/100 kΩ 
 0 V to 10 V/100 kΩ  
•  Current 
± 20 mA/50 Ω 
 0 mA to 20 mA/50 Ω 
 4 mA to 20 mA/50 Ω  
•  Existence 
0 Ω to 600 Ω/10 MΩ  
•  Resistance thermometer 
Pt 100/10 MΩ  
Permitted continuous input voltage (destruction limit)   
•  For voltage inputs 
Max. 30 V 
•  For current inputs 
Max. 2.5 V 
Permitted continuous input current (destruction limit)   
•  For voltage inputs 
Max. 0,5 mA; 
•  For current inputs 
Max. 50 mA;