Siemens Simatic S7-400 User Manual
Page 145
Digital Modules
4-23
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
4.9
Digital Input Module SM 421; DI 16
24 VDC;
(6ES7421-7BH00-0AB0)
Characteristics
The digital input module SM 421; DI 16
24 VDC has the following features:
•
16 inputs, isolated in 2 groups of 8
•
24 VDC rated input voltage
•
Suitable for switches and two/three/four-wire proximity switches
(BEROs, IEC 61131; type 2)
•
2 short-circuit-proof sensor supplies for 8 channels each
•
External redundant power supply possible to supply sensors
•
“Sensor supply (Vs) O.K.” status display
•
Group error display for internal faults (INTF) and external faults (EXTF)
•
Programmable diagnostics
•
Programmable diagnostic interrupt
•
Programmable hardware interrupt
•
Programmable input delays
•
Parameterizable substitute values in the input range
The status LEDs indicate the process status.