Siemens Simatic S7-400 - Manual (Page 141)

Digital Modules
4-19
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Technical Specifications of the SM 421; DI 32 x 24 VDC
Programming package
Associated programming
package As of STEP 7 V 2.0
Dimensions and Weight
Dimensions W H D
(in millimeters)
25 290 210
Weight Approx. 600 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+ 24 VDC
•
Reverse polarity protection Yes
•
Power failure buffering None
Number of inputs that can be
triggered simultaneously 32
Isolation
•
Between channels and
backplane bus Yes
•
Between channels and
power supply of the
electronics No
•
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. 30 mA
•
From supply voltage L+ Max. 30 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
Sensor Selection Data
Input voltage
•
Rated value
•
For signal “1”
•
For signal “0”
24 VDC
11 V to 30 V
–3 V to 5 V
–30 V to 5 V as of
version 03
Input current
•
At signal “1” 6 mA to 8 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 2
Connection of two-wire BEROs Possible
•
Permitted bias current Max. 2.5 mA