Siemens Simatic M7-400 Reference Manual page 178

Digital Modules
4.15 Digital Input Module SM 421; DI 32
(6ES7421-1EL00-0AA0)
Characteristics
The SM 421; DI 32
• 32 inputs, isolated
• Rated input voltage 120 VAC/VDC
• Suitable for switches and two-wire proximity switches
4-56
120 VUC is characterized by the following features:
S7-400, M7-400 Programmable Controllers Module Specifications
120 VUC
;
A5E00069467-07