Digital Modules
4-44 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
4.12 Digital Input Module SM 421; DI 16 24/60 VUC;(6ES7 421-7DH00-0AB0)
Characteristics
The SM 421; DI 16 24/60 VUC is characterized by the following features:
16 inputs, individually isolated
Rated input voltage 24 VUC to 60 VUC
Suitable for switches and two-wire proximity switches (BEROs)
Suitable as active high and active low input
Group error display for internal faults (INTF) and external faults (EXTF)
Programmable diagnostics
Programmable diagnostic interrupt
Programmable hardware interrupt
Programmable input delays
The status LEDs indicate the process status.