Siemens Simatic S7-400 - Manual (Page 156)

Digital Modules
4-34
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Terminal Assignment Diagram for Redundant Supply of Sensors
The figure below shows how sensors can additionally be supplied by means of Vs
with a redundant voltage source – for example, via another module).
Vs
M
L+
1 L+
2 L+
to the sensors
±
Digital input
module
Short-circuit-
proof driver
Figure 4-7 Terminal Assignment Diagram for the Redundant Supply of Sensors of the
SM 421; DI 16
24 VDC
Technical Specifications of the SM 421; DI 16 24 VDC
Dimensions and Weight
Dimensions W H D
(in millimeters)
25 290 210
Weight Approx. 600 g
Data for Specific Module
Number of inputs 16
Length of cable
•
Unshielded
input delay
– 0.1 ms
– 0.5 ms
– 3 ms
Max. 20 m
Max. 50 m
Max. 600 m
•
Shielded
input delay
– 0.1 ms
– 0.5 ms
– 3 ms
Max. 30 m
Max. 70 m
Max. 1000 m
Voltages, Currents, Potentials
Rated supply voltage of the
electronics and sensor L+ 24 VDC
•
Reverse polarity protection Yes
Number of inputs that can be
triggered simultaneously 16
Isolation
•
Between channels and
backplane bus Yes
•
Between channels and
power supply of the
electronics No
•
Between the channels Yes
– In groups of 2
Permitted potential difference
•
Between the different
circuits 75 VDC, 60 VAC
Insulation tested with
•
Channels against
backplane bus and load
voltage L+ 500 VDC
•
Channel groups between
themselves 500 VDC
Current consumption
•
From the backplane bus
•
From the power supply L+
Max. 130 mA
Max. 120 mA
Power dissipation of the
module Typ. 5 W