SIEMENS Digital modules SM 321 digital input modules
For connecting standard switches and two-wire proximity switches (BEROs)
SM 321 digital input modules Application
Digital input modules can be used to connect the PLC to digital process signals. They are suitable for connecting standard switches and two-wire proximity switches (BERO).
SM 321 digital input modules Design
Digital input modules feature the following mechanical characteristics:
Compact design: The rugged plastic housing contains:
Green LEDs for indicating the signal status at the inputs.
Socket for the front connector, protected, behind the front door.
Labeling field on the front door.
Connector pin assignment for the wiring on the inside of the front door.
Easy installation: There are no slot rules, the addresses of the inputs are determined by the slot. When used in ET 200M in combination with active bus modules, hot swapping is possible without any reaction.
The modules are available with 8, 16, 32, or 64 channels.