Digital Modules
4-43
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Technical Specifications of the SM 421; DI 16 120 VAC
Dimensions and Weight
Dimensions W H D
(in millimeters) 25 290 210
Weight Approx. 650 g
Data for Specific Module
Number of inputs 16
Length of cable
•Unshielded
•Shielded
600 m
1000 m
Voltages, Currents, Potentials
Number of inputs that can be
triggered simultaneously 16
Isolation
•Between channels and
backplane bus Yes
•Between the channels Yes
– In groups of 1
Permitted potential difference
•Between Minternal 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. 0.1 A
Power dissipation of the
module Typ. 3.0 W
Status, Interrupts, Diagnostics
Status display Green LED per
channel
Interrupts None
Diagnostic functions None
Sensor Selection Data
Input voltage
•Rated value
•For signal “1”
•For signal “0”
•Frequency range
120 V
72 to 132 VAC
0 to 20 V
47 to 63 Hz
Input current
•At signal “1”
•At signal “0”
6 to 20 mA
0 to 4 mA
Input delay
•At “0” to “1”
•At “1” to “0”
2 to 15 ms
5 to 25 ms
Input characteristic curve To IEC 61131; type 2
Connection of two-wire BEROs
•Permitted bias current
Possible
Max. 4 A