S7-400 Signal modules

Modules 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, electrical 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.

Design and function

Easy installation
The sensors/actuators are connected through front connectors. When a module is replaced, the connector is simply plugged into the new module of the same type; the wiring is retained. The coding of the front connector avoids mistakes. The S7-400 is also able to detect whether the front connector is plugged in.

Fast connection
SIMATIC TOP connect makes connection even simpler and faster. Preassembled front connectors with single cores and a complete plug-in modular system comprising a front connector module, connecting cable and terminal block are available.

High packing density
The high number of channels on the modules is a reason for the space-saving design. For example, modules with 8 to 32 digital channels or 8 to 16 analog channels are available.

Simple parameterization
The modules are configured and parameterized using STEP 7, and there are no inconvenient switch settings to be made. The data are stored centrally and, following module replacement, they are automatically transferred to the new module so that no setting errors can occur. No software upgrade is requiredwhen using new modules. A configuration can be copied as often as required, e.g. for standard machines.

Diagnostics, interrupts
Many modules additionally monitor signal acquisition (diagnostics) and the signals from the process (process interrupt. e.g. edge evaluation). This makes it possible to react immediately to process errors, e.g. wire breaks or short circuits, and any process event, e.g. rising or falling edge at a digital input. The response of the controller can easily be programmed with STEP 7. On the digital input modules, several interrupts per module are possible.