Siemens Simatic S7-400 - Manual (Page 144)

Digital Modules
4-22
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Technical Specifications of the SM 421; DI 32 x 24 VDC
Dimensions and Weight
Dimensions W H D
(in millimeters)
25 290 210
Weight Approx. 500 g
Data for Specific Module
Number of inputs 32
Length of cable
•
Unshielded
•
Shielded
Max. 600 m
Max. 1000 m
Voltages, Currents, Potentials
Power rated voltage of the
electronics L+ Not required
Number of inputs that can be
triggered simultaneously 32
Isolation
•
Between channels and
backplane bus Yes
•
Between the channels No
Permitted potential difference
•
Between the different
circuits 75 VDC / 60 VAC
Insulation tested with
•
Channels against
backplane bus and load
voltage L+ 500 VDC
Current consumption
•
From the backplane bus Max. 20 mA
Power dissipation of the
module Typ. 6 W
Status, Interrupts, Diagnostics
Status display Green LED per
channel
Interrupts None
Diagnostic functions None
Substitute value can be applied No
Data for Selecting a Sensor
Input voltage
•
Rated value
•
For signal “1”
•
For signal “0”
24 VDC
13 V to 30 V
-30 V to 5 V
Input current
•
At signal “1” 7 mA
Input delay
•
At “0” to “1”
•
At “1” to “0”
1.2 ms to 4.8 ms
1.2 ms to 4.8 ms
Input characteristic curve To IEC 61131; type 1
Connection of two-wire BEROs Possible
•
Permitted bias current Max. 1.5 mA