Description
SIMATIC S7-400, digital input SM 421, isolated 32 DI; 120 V DC/AC6ES74211EL000AA0_datasheet_en
Overview
Signal modules are the interface of the controller to the process.
A host of different digital and analog modules provide exactly the inputs/outputs required for each task. Digital and analog modules differ as regards the number of channels, voltage and current ranges, isolation, diagnostics and alarm functions, etc.
However, the S7-400 signal modules are only a subset of the modules that can be connected to the S7-400 via PROFIBUS DP.
Centrally connected signal modules can be connected and disconnected during operation.
This makes module replacement extremely easy.
In all the module ranges listed here, SIPLUS components are also available for corrosive atmospheres/condensation.
