Digital Modules
4-58
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Technical Specifications of the SM 421; DI 32 120 VUC
Dimensions and Weight
Dimensions W H D (mm) 25 290 210
Weight Approx. 600 g
Data for Specific Module
Number of inputs 32
Length of cable
• Unshielded
• Shielded
600 m
1000 m
Voltages, Currents, Potentials
Rated load voltage L+ 79 to 132 VAC
80 to 132 VDC
• Reverse polarity protection Yes
Number of inputs that can be
triggered simultaneously
32
Isolation
• Between channels and
backplane bus
Yes
• Between the channels Yes
– In groups of 8
Permitted potential difference
• Between M
internal
and the
inputs
120 VAC
• Between the inputs of the
different groups
250 VAC
Insulation tested with 1500 VAC
Current consumption
• From the backplane bus Max. 0.2 A
Power dissipation of the
module
Typ. 6.5 W
Status, Interrupts, Diagnostics
Status display Green LED per
channel
Interrupts None
Diagnostic functions None
Data for Selecting a Sensor
Input voltage
• Rated value
• For signal “1”
• For signal “0”
120 VUC
79 to 132 VAC
80 VDC to 132 VDC
0 to 20 V
• Frequency range 47 to 63 Hz
Input current
• At signal “1”
• At signal “0”
2 mA to 5 mA
0 to 1 mA
Input delay
• At “0” to “1”
• At “1” to “0”
5 to 25 ms
5 to 25 ms
Input characteristic curve To IEC 61131; type 1
Connection of two-wire BEROs
• Permitted bias current
Possible
Max.1 mA