Siemens SIMATIC S7-400 Reference Manual page 128

Digital modules
4.13 Digital input module SM 421; DI 32xUC 120 V (6ES7421-1EL00-0AA0)
Cable length
● unshielded
● shielded
● Reverse polarity protection
Number of inputs that can be enabled simultaneously
Electrical isolation
● Between channels and backplane bus
● Between channels
Permissible potential difference
● Between M
● Between inputs of different groups
Insulation tested at
Current consumption
● From backplane bus (5 V)
Module power loss
Status display
Interrupts
Diagnostic functions
Input voltage
● Rated value
● For "1" signal
● For "0" signal
● Frequency range
Input current
● For "1" signal
● For "0" signal
Input delay
● For "0" to "1"
● For "1" to "0"
Input characteristic
Connection of 2-wire BEROs
● Permissible quiescent current
128
in groups of
and the inputs
intern
600 m
1000 m
Voltage, current and potential
Yes
32
Yes
Yes
8
120 V AC (reinforced insulation)
250 V AC (basic insulation)
1500 V AC
Maximum 200 mA
Typ. 6.5 W
Status, interrupts, diagnostics
Green LED per channel
None
None
Data for selecting a sensor
UC 120 V
79 to 132 V AC
80 to 132 V DC
0 to 20 V
47 to 63 Hz
2 to 5 mA
0 to 1 mA
5 to 25 ms
5 to 25 ms
In accordance with IEC 61131; type 1
Possible
Maximum 1 mA
Reference Manual, Ausgabe 11/2016, A5E00850736-08
S7-400 Automation System Module Data