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.