Siemens SIMATIC S7-400 Reference Manual page 114

Digital modules
4.10 Digital input module SM 421; DI 16 x UC 24/60 V (6ES7421-7DH00-0AB0)
Number of inputs
Cable length
● Unshielded, input delay
● Cable length, shielded
Number of inputs that can be enabled simultaneously
Electrical isolation
● Between channels and backplane bus
● Between channels
Permissible potential difference
● Between different circuits
Insulation tested at
● Channels to backplane bus and load voltage L+
● Between channels
Current consumption
● from backplane bus (5 V)
Module power loss
Status display
Interrupts
● Hardware interrupt
● Diagnostic interrupt
Diagnostic functions
● Group fault display
● Channel fault display
● Diagnostic information can be read out
Monitoring for
● Wire break
Substitute values can be connected
Input voltage
● Rated value
● For "1" signal
● For "0" signal
Frequency range
114
0.5 ms
3 ms
10 / 20 ms
in groups of
for internal fault
for external fault
16
Maximum 100 m
Maximum 600 m
Maximum 600 m
1000 m
Voltage, current and potential
16
Yes
Yes
1
60 V DC/30 V AC (SELV)
1500 V AC
1500 V AC
Maximum 150 mA
Typ. 8 W
Status, interrupts, diagnostics
Green LED per channel
Configurable
Configurable
Configurable
red LED (INTF)
red LED (EXTF)
None
Possible
I > 0.7 mA
No
Data for selecting a sensor
UC 24 to 60 V
15 to 72 V DC
- 15 to -72 V DC
15 to 60 V AC
DC - 6 to +6 V
AC 0 to 5 V
DC/AC 47 to 63 Hz
Reference Manual, Ausgabe 11/2016, A5E00850736-08
S7-400 Automation System Module Data