Siemens simatic c7-621 Hardware Installation Manual page 96

C7-621 Analog I/Os
Analog Input The following table contains the technical data of the analog inputs of the C7
CPU.
Module-Specific Data
Number of inputs
Cable length
Shielded
Voltages, Currents, Potentials
Permitted potential difference
Between inputs and M
ANA
(U )
CM
Analog Value Formation
Measuring principle
Conversion time/resolution
(per channel)
Base conversion time
Resolution (including
overflow range)
Noise Suppression, Error Limits
Noise voltage suppression
Common mode voltage
(U < 1.0 V)
CM
Crosstalk between inputs
Error limit (in the entire
temperature range related to
the input range)
Voltage input
Current input
7-14
Noise Suppression, Error Limits, continued
4 Basic error limit (operational
limit at 25 C relative to input
range)
max. 100 m
Voltage input
Current input
Temperature error (relative to
input range)
DC 1.0 V
Linearity error (relative to
input range)
Reproducibility accuracy (in
Instantaneous value
settled state at 25 C, relative
encoding (successive
to input range)
approximation)
Status, Interrupts; Diagnostics
Interrupts
100 s
Diagnostic functions
11 bits + sign
Data for Selecting a Sensor
Input ranges
(rated values)/input resistance
Voltage
> 40 dB
Current
> 60 dB Permitted input voltage for
voltage input (destruction
limit)
Permitted input current for
1.0 %
current input (destruction
1.0 %
limit)
Connection of sensors
for voltage measurement
for current measurement
as 2-wire transducer
as 4-wire transducer
0.9 %
0.8 %
0.01 %/K
0.06 %
0.06 %
none
none
10 V/50 k
20 mA/105.5
max. 30 V permanent;
38 V for max. 1 s
(pulse duty factor
1:20)
34 mA
possible
not possible
possible
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01